I always liked these and I had a chance to get one several months ago at a reasonable price since it apparently was one of the early ones with electrical issues. I run conventional and the only things I could get to work were the smoke and the lights. A big plus, the DC motors for the doors and the shop machinery were operational. Lionel has an upgrade for around $130 to replace the electronics but it won't support conventional operation. So I decided to do a lobotomy and here is what I did in case anyone needs to do this. Parts used:
1) RF 4 channel relay switch. 2) buck converter. 3) ITT sound module. 4) Henning/ GRJ LED light system to brighten the interior. 5) rectifier, capacitor and an external on off switch. (the NW shop sign is optional)
Here are the details, not quite perfect documentation but it will give you the idea. I used the four channels on the RF fob to turn on the smoke, machinery / noise, and raise / lower the doors. the switches on the unit to sense door up and down are reused also along with the speaker.