If I'm not mistaken the shoes are made of corrected grain. Saphir Renovateur has close to no efffect on CG, however, using nail polish remover could have removed the top layer of the finishing, which IMO is destroying the shoes.
Thank you very much for your post, highly appreciate getting another point of view; really opened my eyes. I will surely take it for thought for later, and not treat my other shell cordovan the same way. So for people buying vintage shell cordovan, follow this guy's advice! However, I will keep on documenting on the effects the Obenauf's going to have on my Florsheims.