Dismantle spun-in lens cells?

[John Marriage]

Has anyone succeeded in extracting the glass from a lens cell which is secured by a thin metal lip being spun over the edge of the glass? I have a ~100-year-old wide angle rectilinear by C Burr, generally good but with badly separated and yellowed cement holding the rear cell together. I can easily unscrew the whole thing - a brass ring unscrews from the barrel. But to get the glass out, to re-cement it, requires the curled-over metal to be curled back. Or cut off, but then what? It would be all too easy to make things much worse here! Any past experiences, good / bad, welcomed.

[John Koehrer]

The lip can be carefully unfolded, but will be somewhat marked when you reassemble, I use a very small dental probe with a flat edge. The edge is on the order or an X-acto blade. You need to work around the perimeter several times, very gently.
The edge can be folded back with a plastic tool or knife of some sort

[johnielvis]

I'd cut it like a can opener and make a new threaded front mount for the barrel...cut from outside with nice precision tool and you don't mess up the glass...of course i've never done it, but that's what I'd do

[Jason Greenberg Motamedi]

I have opened them at home using small tools, as John Koehrer describes. The result is functional, but looks crappy when folded back. With more valuable lenses I have sent them to John at Focal Point to do the work and re-cementing. I am sure that the Grimes boys could do it too.

[TheDeardorffGuy]

The ONLY safe way is to use a lathe and a 4 jaw chuck to cut it off. I turn the chuck by hand. never use the motor. thats called a burnished mount