There was a Norman J. Englebrecht that used to shoot with the Fort Dearborn club in Illinois. I know he made at least a few rifles--more as a hobby than anything and could be the maker of your pistol. Norm lived in Palatine, Il. with his wife Elizabeth. It might be possible to look him up on the internet and give him a call to verify. I believe he would be in his mid 70's by now.
Good luck!