Don't forget to contact Mark in the post above to see if he has the parts you need first.
I'm going to post the contact info here so I don't have to tear the house apart again looking for it. The toll free number for Sun Parts is 800-225-5786, but they only carry parts for their current items they have for sale - and they don't sell a distributor machine anymore.
The man you need to talk to for ordering parts is Roger Kunz, and his phone number is 815-344-6538. He can get absolutely any part for the machines, and is a pleasure to talk to on the phone. He can also point you to people that still service these machines. They are retired Sun techs, and the only problem is that they are located around Illinois (okay, only a problem for those of us on the west coast). You need to note whatever numbers you can find on the seperate pieces on the machine. I didn't know it, but the shell can contain any assortment of add on items. For example, there might be a dozen different dwell meters that would fit in the cabinet.
The amplifier module was a little lightweight box that is fully self contained and measures about 4x6x2 and has two brass terminals on top. You put your distributor lead on the + terminal and a ground lead to the - terminal. No batteries, no external power, but you fire up the distributor and everything works. Strange, but it does exactly what it is supposed to do.
I found out later that it is not needed for Unilite or the new Crane XRi modules, and all you need for these is an external power source.