During one of my eBay explorations I bid on one of those batch auctions in order to get a couple of the included items. In addition to what I was looking for, I received a 135mm Ektanon Enlarging lens. My Beseler 67 enlarger only goes up to 6x7, but I thought that it might be useful to have the 135mm lens on a board, for those times like the postcard exchange when I wanted small prints from larger negatives.
The Ektanon lens was larger than the 39mm standard thread (about 42mm IIRC) so I had a machine shop cut the hole in a blank lensboard I had. Unfortunately, that was wasted money - the bellows on my Beseler enlarger doesn't extend far enough to focus the 135mm lens.
Oh well, it is the lessons you learn...
You can use either wood or aluminum plates stacked, drilled in the four corners and drilled in the middle to extend the lens a couple of more inches. The machine shop probably could do it without to much expense. If you need a photo of something similar, I can send you one from a Durst enlarger that is mount like this.