Today I had time to do something. I had bought a new battery, normal size. It didn´t fit to battery tray. Someone had noticed that thing before and done some cutting and hammering.
I cut that tray in two and hammered that edge like it should be.
Then it was time to do some measuring... 7/8" it was or 22 mm.
Now it looks much bigger.
More welding and some testing. Tight fit... had to open little those bolt holes. Now final weld and then paint...