Might be worth popping the cover off the old fuel pump relay and cracking out the soldering iron. The relay became intermittent on my 924 which resulted in weird running issues (suspect it would have 100% died at some point) but when I removed the cover I could see some of the solder joints were looking old. Reflowing all the solder joints I could reach solved the issues and its still going fine 2 years later.
New ones are really hard to find and usually silly money - this guy has built alternatives but no idea how reliable they are:
https://norx-electronics.hu/?page_id=1217