OK, the fan is replaced. Several things I learned:
There are 6 screws in the bottom of the case that have to be removed. A long T-handle 3 mm Hex key works very well. These are definitely NOT Torx screws.
The fan is actually 60mm square, and 18mm thick.
The fan is wrapped on the edge with open cell foam. Its not worth trying to reuse it, so having some available is wise. Figure 1/4" thick, and ~1x 10".
I used a CPU cooling fan I picked up at my local computer store. The connector is not the same as what MTH uses. I ended up cutting off both connectors and splicing the old connector to the new fan. I insulated the solder joints with heat shrink tubing.
I tried not to disturb the main transformer, but ended up having to so do anyway. The wire for the fan goes in a channel underneath it, and got tangled up with the other wires. I paid close attention to all the wires so that nothing got pinched in reassembly. Speaking of which, a clawed screw retriever is a very useful tool when reinstalling the screws.
To the voltage leak: I put a 18v bulb across each pair of posts for the variable output. With the bulbs in place, the outputs each read 0.5v. I guess as long as it does not climb further, I can live with it. I will keep an eye on it.
G- Do you have a diagram of the main board showing the locations of the pins you mentioned?
GRJ- I'm not up on ordering component parts, at least caps. I'll have to pay you a visit at Henning's sometime for an education.
