I just found some after market mags being sold as "for RIA 1911A2" 15 round 9mm mags.
They fit, and seem to function.
They have Llama stamped on the body of the mags.
Greg Cote LLC Rock Island Armory 9mm-.38 Super 1911 A2 17 RD nickel Mec-Gar MGP183817N [MGP183817N] - Armscor Rock Island Armory 9mm or .38 Super 1911 A2 and Armscor 1911 A2 FS PS, Para Ordnance P18 17 RD 9mm magazine Mec-GAr MGP183817N. These are double stack MAGAZINES; they DO NOT fit single...
gregcotellc.com
If those are the ones you can sign up to get an email once they are back in stock.