Most likely someone's aunt painted them, bought cheap Mexican frames and put the pictures in then got sick of them and put them in a garage sale.
But they could, I suppose be original Diego Riveras...
No one will be able to tell you anything unless they see atleast a picture of the paintings.
Linda C

Here are the pictures in the above post......and I don't think these are by someone's aunt....unless that aunt was a skilled artist.
{{gwi:1375900}}
And another:
{{gwi:1375901}}

The Windmill at Wijk bij Duurstede is a very similar painting. You probably have a copy.

Hecho en Mexico means "made in Mexico", but I'm sure you knew that.

Here is a link that might be useful: The Windmill at Wijk bij Duurstede

A ta-dah moment and a bit of internet wearching.....and enlarging the photo that was sent...made the light bulb go on!
What you have is a print that has been printed onto a canvas like background and then doctored, or decorated or whatever, with a modge-podge sort of stuff to give it some texture and make it look sort of like an oil painting.
The original by Jacob von Ruisdael is much too famous for you to find it in a garage sale set into a bad Mexican frame.
The pictures are decorative.....certainly not worth spending anything on restoring, if that were possible. I would get that bad black ...looks like velvet, mat out of that frame, spray the frame gold and rub some walnut stain over the gold paint and enjoy the pictures for what they are....
Linda C

Get a strong magnifying glass and see if you can see colored "dots": that would be a tip off that's it's printed, no matter what crackle medium might be over it. There is a newer reproduction process now (called "giclee") that shows no dots, but it's recent enough and still expensive enough that it's unlikely that giclee prints would be showing up yet in garage sales.

If you like the paintings, then that's all that matters! Hang them on the wall and enjoy. I would guess the framed paintings (or prints possibly) are worth about $5 to $25 each; therefore, not worth restoring. Best of luck.