The thing is its not a "shyte' autopilot , its has worked faultlessly for over 40 years ! Its a shame to just toss such things away when there are quite possibly a few people skilled enough in traditional avionics to fix it floating around - its just finding them.
Things your Shyte Navomatic 400 A can’t do even when it is working perfectly, that modern auto pilots do:
- Altitude preselect with automatic capture
- IAS hold
- GPSS
- Pitch anticipation for level out
- Envelope protection
- Emergency level
- Digital servos that don’t require periodic expensive calibration
- 1/3 the installed weight
- A warranty
Personally I think you are throwing away money trying to keep 50 year old tech going. I think you are in a pay now or pay later situation and the reality is likely if you want a working auto pilot you will have to buy a new one.