It's not going to be worth the expense unfortunately.
If you want an MX, there are always lots of fully working ones going for next to nothing on ebay.
Regards
Michael
BV5, BV Avant, MX4000, MX1500
BS 7000, BS 5500
Penta III, Penta II, BL 4000, RL 60.2, RL 35, CX-100 Alu
BL 7000, MCP6500, MCP5500, BL 5000, Beo4 (x2), BL 1000 (x2)