I believe the 50mm C, C T* which can focus as close as 19" or 48.26cm, may have been a 1st choice of the Hasselblad line, before there was a macro 120mm and perhaps, the 135mm, with its back protrusion.
Ralph, while these are 6x6cm format lenses, I would no be surprised to see them on a 5x7" or 8x10' enlarger, and I might just tru to make a plate to try the 5cm out on my 5x7 Omega enlarger, in the near future.
If I do, I'll post results.
I'm still working on my 50mm, other things have gotten first priority, here at home, and while the back plate is off, at the least I can make a two piece templet,that can be used to create a brass plate for the enlarger.
Once I have the several replacement screws I need, I can finish the work, it does have nice glass, and give it a go.
Once a plate is made or or made available to me, I could also see if there is any joy in the 15.cm lens, etc.
I'd still like to hear more on this topic, particularly is anyone yet to speak-up, whom has experience in the matter.
Godspeed to all, BE HAPPY!