Should I keep old AP system as a spare?

[WilloCo]

I'm reworking my instruments pretty heavily:

Wind sensor, depth/speed/temp transducer, gps receiver, triton2 mfd, triton2 ap control, NAC-3 autopilot computer, rudder feedback, AIS transponder - everything nmea 2k.

I have a raymarine autopilot system - the mount for the RF sensor broke, but is otherwise complete.

The question in my mind - should I maintain the old AP system as a backup?
It's got a ST7002 head that's working but the screen is sundamaged enough to bug me. I'm probably re-using the existing linear actuator with the new AP (But I'm going to look for a spare and mount it opposite)

OR, do I just scrap the old gear and keep spares for the new system? The Raymarine stuff has a decent value on the used market (that or ebay is just insanely overpriced).

I will have a opencpn system running, which I can interface with either sytstem...