wwin. model 290

This semi auto has a plastic front sight assembly. It is broken between barrel and magazine. There is a up date on repairing.J.W. Peterson in Tavaries, Fl.told me there was a block that was silver soldered to the barrel and had a hole for the magazine to go through.The front sight had to be sloted for the sight. Any information on where to get one of these blocks or how to repair would be appreciated.Thanks in advance.

Grayghost