Help with thermostat

[James Munsell]

I have a older system and want to install a newer thermostat and I'm told by Honeywell it will work but there is 8 wires three of which I don't know what they do. Here is a pic of the old one and the wiring diagram. The new one I want to install is here https://customer.honeywell.com/resources/techlit/TechLitDocuments/69-0000s/69-2206EF.pdf This is a manufactured home, 1986 and the heat pump is a 3400a816 8 wire.

 

[James Munsell]

Lot of people looking but no one knows what goes. lol