Finally able to do some work on the model.  These are photo's of another "House of cards" assemblage of the cab this time.  Obviously a lot of hours of work to do yet but nice to see things shaping up. The side cab windows slide and much detail is yet to be added of course. Headlights, windshield wipers, heater intakes, door hinges, sand box fillers and clean outs etc. etc.  That is AFTER I get it all cleaned up and smoothed out.
This is a three layer lamination of styrene with brass channel and angle used to mount the window material.  I have tried to use glass for years, even bought some and broke it for this model.  Reverted to acrylic which seems to reflect the light pretty much like glass and is a whole lot easier to work with. I'll try the glass in the yard office when I get to it.
I goofed the frame by laying out and installing the diamond plate running boards before I built the cab. Then I changed my mind and added the Um6B type nose, it reminded me of the U33's which I hated to the bone. (There is no explaining humanity) Now the cab won't sit tight on the frame. No problem, the second frame is far enough along to be ready for this cab.  You nit pickers out there can have a field day with this if you want but I guarantee you I can devise a scenario that will cover everthing you find on this engine including the nose. Besides it looks kinda cute on this little bitty U-boat. And the first frame is going to revert to a project that will drive the nit pickers right out of their minds. Bet you didn't know GE built a U6B "B" unit, did 'ya? *

I asked on the Yahoo list if anyone knew of the performance of the Micro-Mark motor and got no response. So I'll ask again here and see if anyone out there who might read this would have had some experience with their product.  The price seems right and all the drive train components fit it so it would be real handy to deal with. Thanks in advance for any advice.

*Actually I've never seen one, but I'm going to imagineer this one just for fun and it will fit my operating scheme just fine. After having wrestled with the cab of this model I've had it for a while, hoods are much easier to deal with !

U6B Cab Assembly