Looking for newer singer versions, I've found that our machine is quite similar to the singer 201K23, but treadle operated... what do you think? The manufacturing years would make more sense to me, but the fact that someone bought a sewing machine treadle operated at that time seems a bit weird. Spain had a hard post-civilwar time, but I believe they already had electricity here! hehe
Singer 201k23:
https://d33wubrfki0l68.cloudfront.ne...23-360x240.jpg
found here:
https://www.singersewinginfo.co.uk/201