ID help with Mid Century Dining Chairs

Howdy... newbies here, but hope you'll see a good bit of us in the future! We've been buying & selling for years and finally invested in a truck large enough to play around with furniture! Here's a set of chairs we picked up ....

Likely the red is a recovering. No makers mark that we can find, only the stamped number you see in the pics: 375-95.

Using words like Danish, Czech, Mid Century Modern, Vintage, open back, etc.... we've found many, many similar chairs, but nothing with an opening of that shape. I think the braces are done in an interesting way with the grooves in the side pieces. (I'm sure they have a specific name.. but newbie, remember?) Help us learn!

Any info appreciated.... if it it's 'blue light special'

 

I don't recognize them and they could be knock-offs. The joinery on the corner blocks is unusual and may be a key to maker. Have seen it before but don't remember on what. Maybe on some pretty generic MCM furniture.

 

Thanks for the reply! On another forum, they were described as mass produced yard sale pieces.... On closer inspection, I suppose that's true. Quick joints, unclean cuts, fiberboard seat. So Mid Century... probably.... well made quality? Probably not. It will be interesting to see what interest we get when we list them!