I have a FWB 300s air rifle and the rear diopter sight has broken with the alloy body breaking cleanly where a pin that holds one side together is. I wondered if anyone knows of any replacement rear diopter sights that fit my 300s. I have a centra screw in eye piece that fitted the original FWB diopter sight and wondered if this would screw into other diopter sights. I have seen an Air Arms 200 rear diopter for sale for around the £30 price tag and wondered if this maybe ok. The rifle is in good usable condition but I dont really want to spend hundreds of pounds on a diopter as I may as well put the money towards a newer rifle or is there some glue or weld paste that I could try and repair the original diopter. Thanks for any advice.