Hi,
I live in the UK and so while I can get a pressure bleeder quite easily, the standard screw-on reservoir cap adapter that comes with it will be useless for an old American car. I have seen clamp-on ones for the commoner rectangular American old-style reservoirs but on the '65 New Yorker the reservoir is circular.
The solution was to cut a roughly circular slab out of a sheet of thick plastic with a matching circle of thick rubber sheet, screw the pressure hose fitting into the center...
DIY pressure bleed adapter for circular reservoir on '65 New Yorker
