Chris,
I saw on E bay that someone is selling the manuals for Federal enlargers. I know that Federal made a 4X5 model, but I don't know which models were for which formats. I would spend the money for the manual or find someone who is selling a Federal so you can see if you can fit a modern lens on it. I used a federal when I was station in Italy. 8x10 or 11x14 is no problem, and if memory serves me I think Federal's will turn 180 so you print to the floor. The OIC of the photo unit made sure we did not use the photo lab's equipment for non offical use, but there was a small dark room in the base hobby shop and it had a federal in it. Im not sure if it had a lens board, but it had a new lens on it. I think that federal's were point source type enlargers designed to be used with a clear bulb, very high contrast but very sharp, the one I used had a frosted bulb in it. Dust and other negative defects will show up, so you will need good spotting skills.
I have been thinking about a federal as a third enlarger to use a point source to print my older 35mm negatives from the 60's and early 70's which were shot and developed to be high contrast. Let me know what you find out.
Best,
Paul