They are from 1950s and 60s.  If they are original, you probably can get some money (like $200 or $300 and not thousands) for them.  I did a quick search on Google based on the pictures you posted.  My opinion is not professional just a guess based on what is out there…I collect stamps for fun/history and not for monetary value…

These are from the People’s Republic Of China. While there are some valuable stamps from this country in this era, I do believe there are fakes in the marketplace. I personally am not a China stamp expert so I’ll leave this post open in case someone else has more info.

tyy.I have one. If it’s interesting, I can post some valuable pictures.

@bahador37 Greetings and welcome to the Stamp Collectors community.  My apologies for not piping in sooner to your original Post, I was a tad busy enjoying my recent retirement.

As mentioned by @ryanjoneson, many stamps from the People’s Republic of China have been forged or counterfeited to deceive.  With this stated, I am going to provide you with the below information for each with the assumption these stamps are legitimate.

Using the images you provided, I have cropped each for the below write up – please excuse me for having done such causes the images I present below may not be well defined, but quite blurry.

Going chronologically as issued, the ones I’d like to touch upon are a set, of which your photo show you have many copies of each…

Firstly, it must be noted these have been Reprinted after the Originals were issued.  Using the below image to ascertain which you may have (flyspecking involved here, so you’ll need a good magnifier)…

This set depicts The Flag of PRC, Mao Tsetung, and the Gate of Heavenly Peace were Designed by Sun Chuanzhe, Zhang Ding and Zhong Ling.  The Originals were printed by “Printing Plant of Da Dong Book Company, Shanghai”, while the Reprints (officially sanctioned) were printed by “Shanghai No.1 Printing Works”.

Both were issued by the Ministry of Post and Telecommunications of the PRC (Originals issued on July 1st, 1950 and Reprints issued on January 10, 1955) are Unwatermarked, Offset Lithography, and NGAI (No Gum as Issued).  The Original versions are Line Perf 14, while the Reprints are Line Perf 12.5

I’m back to tackle the rest.  Unfortunately, I am unable to locate any information on The Designers and Printers of the remaining stamps upon your initial Post.

Now for the next two stamps which are from the Series titled “Cultural Revolution”…

Scott # 920 Issued on December 31st, 1966, depicts “Athletes Holding Little Red Books and a Portrait of Mao”, Unwatermarked, Perforation Comb 11, Photogravure, CV Unused $90.00.

If you utilize other Catalogues in lieu of Scott, here are the most popular Catalogues out there along with this stamp’s Cat # for your reference…

Michel # 948

Stanley Gibbons # 2325

Yvert et Tellier # 1705

Scott # 921 Issued on December 31st, 1966, depicts “Athletes Reading Mao Text” (“1st Sports Festival of the New Asian Movement”), Unwatermarked, Perforation Comb 11, Photogravure, CV Unused $90.00.

If you utilize other Catalogues in lieu of Scott, here are the most popular Catalogues out there along with this stamp’s Cat # for your reference…

Michel # 949

Stanley Gibbons # 2326

Yvert et Tellier # 1706

To Be Continued on the next Post…

I’m back.  Again, my apologies, I am unable to locate any information on the Designers and Printers of the remaining five stamps upon your initial Post.

All are from the Series titled “Labour Day”, Unwatermarked, Perforation Comb 11 x 11.5, Photogravure and Recess, Issued on May 5th, 1967.

Scott # 949 depicts “Gate of Heavenly Peace and Text from CCP Communique Praising Mao” – CV Unused $140.00.

Scott # 950 depicts “Mao and Poem” – CV Unused $140.00.

Scott # 951 depicts “Mao Among People of Various Races” – CV Unused $140.00.

Scott # 952 depicts “Mao Facing Left and Red Guards with Books” – CV Unused $140.00.

Scott # 953 depicts “Mao with Upraised Righthand” – CV Unused $175.00.

If you utilize other Catalogues in lieu of Scott, here are the most popular Catalogues out there along with this stamp’s Cat # respectively for your reference…

Michel # 977, 978, 979, 980, and 981

Stanley Gibbons # 2354, 2355, 2356, 2357, and 2358

Yvert et Tellier # 1731, 1732, 1733, 1734 and 1736 (it appears # 1735 was skipped for some reason, no annotation to explain why can be located).

I hope the above, as well as the previous Reply Posts prove beneficial.

Dagnabbit!  My apologies @bahador37 it appears the first Reply Post is incomplete; I may have accidently deleted a portion of my write up with relation to these stamps…

Please refer to the following:

800 Chinese Dollar – Scott # 31 – CV Unused $60.00

1000 Chinese Dollar – Scott # 32 – CV Unused $85.00

2000 Chinese Dollar – Scott # 33 – CV Unused $100.00

3000 Chinese Dollar – Scott # 34 – CV Unused $150.00

If you utilize other Catalogues in lieu of Scott, here are the most popular Catalogues out there along with their stamp’s Cat # respectively for your reference.  Please note, the Michel Catalogue is the only one which differentiates between the Original and the Reprints of which I shall represent the Reprints in parentheses ()…

Michel # 31I (31II), 32I (32II), 33I (33II), and 34I (34II)

Stanley Gibbons # 1432, 1433, 1433, and 1434

Yvert et Tellier # 849, 850, 851, and 852

Again, my apologies for my faux pa with deleting the last portion of my first Reply Post.

I hope the above information proves beneficial.

Thank you @jblaha for picking this one up. I said I would leave it open for someone with more China knowledge, and this is exactly what I was hoping for.

@bahador37 Jan’s breakdown is a great place to start. For stamps at these values I would still get a certificate before selling.