Ask around. You might be able to find one. Also check Craigslist. YOu should be able to find one for short money. My personal favorites are the older Mirros. You can get the gaskets at Ace Hardware. I also have an old Sears that I converted from dial to weighted gauge. I dont like the dial gauges as they can be inaccurate and should be tested every year. The All Americans are nice but I dont think they are worth the price. A gasket will last you many years if you take care of it and spares are cheap. The gaskets on both my Mirros are probably 20+ yrs old and work fine.
How did you convert it to a weighted gauge?