Are these Jens Risom?  

1. Facebook Jens Risom

The upholstery job on these leave much to be desired and aren’t original. My sister had them redone for about 1,000 and I think they turned out pretty bad imho

Looks like they could be model U-416 as listed by Wright Auctions with reference to 1955 manufacturer's catalog.  But something looks off with shape of back, maybe from the reupholstery, or could just be camera angle of photo. 

https://www.wright20.com/auctions/2020/09/american-design/407

If you don't want to sell yourself, you can contact Wright and they will give you an idea on authenticity and what they think they would sell for.  They are in Chicago but also have Rago in NJ and LAMA in LA.  Or if you have a reputable auction house near your location, you could save the shipping cost.  

Thank you so much for the info!

I’ll contact them for more info. My mom found these at a garage sale for $25 each. 🙂

Looking at both 1955 and 1959 catalogs. I believe your chairs are legit Risom U-416. The framing geometry and joints appear to be the same. And while Foster McDavid did make very close knockoffs of the Risom C-140 (and 142), I do not believe they did any knockoffs of the U-416.

The corner blocking underneath the seats are not the simple triangular geometry that I see in the Risom chairs I currently own, but maybe there was a specific reason why they needed to be kinked in this design?