Robert T Hayes “the coal miners gear” prints???

I have these 2 “the coal miners gear” prints. Group 1 and group 2. Robert T Hayes. Can anyone provide me with more information about these prints and the artist? There’s not much I can find on it. It had two certificates of authenticity tucked in the back. With plate numbers for each. The signature appears to be pencil. Just any information anybody can give me about them/him, even how small, would be great. Thank you.

 

Born Ohio 1915.

Ohio County Times News May 11 1978

 

An internet search eventually brought up this.

Debora

 

Your letter of authenticity is to verify there are only 1500 prints and artist usually sign limited addition prints in Pencil.

 

They look like they were in the sun too long

 

Think they're behind non-glare glass.

Debora

 

They do look as if the red and yellow inks has faded making them too blue.

 

Magenta and yellow, technically. You may well be right.

Debora

 

For comparison.

Debora

 

See lots of these similarly affected prints in U.K. Charity shops.