Thrift find - 3 big sports paintings by 2 different artists?

I saw these big (2 largest are 38.5" x 33.5") sports paintings coming off the truck at a local thrift store and my first thought was Roy Lichtenstein (I know, I know! - it was the tennis player I saw first & Lichtenstein was my 1st thought!). They was dust on all of them & it was obvious they'd been in storage a long time.
My friend who is the manager said he wanted $75 each but agreed to $200 for the 3.
I didn't realize until I got home that there were 2 different signatures among the 3 - I just assumed they were by the same artist because they came in together & looked so similar.
Has anyone seen anything by either of these artists? Could they be by the same artist who maybe got married & changed part of their name?
It seems unusual for such similar paintings both having Rieger in the signatures and be by different artists, right?

Any thoughts on these or info on the artists would be greatly appreciated - thank you!

 

Barbara Rieger Mittelmann. Apparently has a number of paintings in the football hall of fame. Yours certainly look like paintings. I would take a close look to make sure they are not giclees. Auction results I could find were a pass at $200 and 1 sold for $100, same size as yours. By the way I think you meant to say Leroy Niemann, not Roy Lichtenstein.

 

Thank you Lithographer!!
PS. No I thought Lichtenstein; I know they're not cartoonist so maybe because the figures were so large in ratio to the canvas? (I honestly don't know why I thought that - probably should have kept it to myself!)
Thank you again - these have become a little bit more valuable!
PSS - they are paintings; you can see/feel little blobs if paint in certain spots.

 

That Rams/Brownies painting ought to sell well, if you're selling.

 

I tell people coming to my estate/garage sales "Everything is for sale except the house!"
I googled her name with football Hall of fame and still couldn't find her - I think it's the search engine my Acer uses - is rather install Google but it's still new and under warranty.

 

When I bend over "if you can see it, it's probably for sale." (LOL)