If you need to go into the system for say new compessor, new hoses, new condensor, new whatever sure it pays to convert.
If your pressure is just a wee bit too low to activate the switch to run, then I would hunt down a can of R12 and try some stop leak and tighten a few hose connections and check the accumulator fitting for a leak, or check the whole system if you can.
Depends on what is needed whether to convert or not.
My GN only needed one can of R12 so I still use it.
I converted salvageV6 the WE4 over to 134A when I changed the compressor out.
What are your guys thoughts on "Freeze 12" , an r-12 substitute [designed for r-12 systems] for a fraction of the cost? I can find it here for $6.60/can. I'm debating stock piling some for the future. [to help pay for future mods ]