Thank you for the feedback.
So in summary: If the out port on the flow cell is venting to atmospheric pressure, it will likely survive, but a bigger problem is that it is dimensioned for a different set of flow/concentration conditions than those seen in HPLC.
I may have formulated my question poorly though. I am not going to attempt re-purposing the flow cell in another detector. I was planning on using the entire optical module from the FPLC, complete with flow cell, deuterium lamp, grating, lenses etc. and detector.
The detector requirements are basically none, since I am doing this in my spare time. The flow cell does not mention volume, but has a path lenght of 100 µm, which might be a bit on the small side for the very dilute solutions encountered in anylytical HPLC.
Another option I'm considering is to construct a fiber optical flow cell from a PEEK cross fitting, with a fiber to a photodiode and one to a spectroscopic light source. Something like this has been reported in literature, I believe.
But I agree, finding a second hand detector is definitely easiest.
--Chris