I'd say gold lacquer, brush applied, using 3M Scotch Blue Automotive Masking Tape to mask off the cabinet. It's what the motor trade use. It adheres well, paint doesn't crepe underneath the edges, and it peels off without pulling the varnish or paint off to which it's been applied. It's thinner but stronger than decorating masking tape. I haven't done anything on the scale of your Murphy A272C, but I did restore the cabinet of a Pilot Little Maestro T105 which was a gaudy turquoise colour with a gold edge and stripes and was in rather a bad way. After removing the old paint, re-spraying it with acid etch primer, an undercoat and colour matched gloss, I masked it off the Scotch blue tape and applied a couple of coats of gold lacquer.
Before & after pics below.
This is the Scotch auto tape I'm referring to. It comes in a range of widths from 19mm to 48mm. (19mm is more than adequate for our needs):
https://www.ebay.co.uk/itm/3M-Scotch...frcectupt=true
Hope that might help a bit.
Good luck with the restoration.