My Tri-mark latch is a bit different than that but I had a shop make me a new striker bolt when the last one broke... Price for the one in the kit is reasonable
On my basement doors (Also tri-mark) slightly different bolt. Seneca Engineering in Seneca, SC carved me a batch of 'em I think about the same price.. Can't find the dang things so I used Plan B a few days ago.. (one of the many jobs I've held.... machienist.. I machine down the parts. mark, drill, tap and apply a standard steel mending bar to the "Backside (The long flat side) works great)