You can't beat a nob mod and this is probably one of the most useful ones for retro games!!!!
Here you'll the breakdown and modification steps to fit a spinner to your Atari Jaguar for use with Tempest 2000.
The rotary encoder I used was:
Bourns 24 Pulse Mechanical Rotary Encoder PEC11R-4220K-S0024 6mm Knurl Shaft
00:00:00 Intro
00:03:27 Disassemble
00:03:57 Controller PCB
00:04:45 Soldering points
00:07:15 Case mod
00:08:26 Testing