this came in from a visitor named Jay:
“The Home Depot has a universal latch made by Wright for 1 1/2″ storm doors. It has 3″ hole spacing just like my door. You may need shims to build up a mount for the strike plate (they provide them for free if you call). I re-spraypainted the original knob and kept it, instead of using the new knob, which is not very big compared to the original. Of course, the latch is the part that I needed to replace on the original, and it is a lever handle type, instead of one of those with a retracting plastic piece that eventually begins to wear out. Keep the replacement knob in case the original’s springiness wears out, but I don’t anticipate any problems with the old one. The new one cost $8.97 as opposed to Forever Door’s $43.00!! The gent in the doorknob dept. at the Home Depot was quite impressed with my solution, as he was sending many customers to millwork to special order new sets ($$$). There are a lot of these doors in this area (Buffalo). I’ve fixed two so far.”