29er frame, Old castle-top style Nimbus

So, after building myself an Epic 29er Plus setup, as feared my frame clearance is not quite up to the job!
I call to you folks, the wonderous unicyclist community of the world and request sale or swappage of the aforementioned Old castle-top style Nimbus frame!
If you have one and have no need for it and wish to sell, I’d be interested, alternatively I could swap my 29er frame with it’s rounder style top? (42mm bearing shells)
thanks in advance!

I’ve got a purpose built 29 plus waltworks that wasn’t my cup of tea if you are interested.