I've looked into premade options for replacing these lights. None to be had.
I told the customer that I would get pricing for custom made replacements, so here's the brief:
I need three MR11 sized LED modules 25mm dia. with built-in circuitry to work on 120VAC with 6" leads like those pictured in my OP. Single, high output LEDs would be fine vs the array style originals. Optimal would be 2700-3000K LEDs in the 80-200 lumen range. Potting the back side to insulate the 120V areas would be recommended, although once installed, there is no possibility for accidental contact.
Additional information:
The 120V supply is controlled by a dimmer switch so voltage will be variable. If it's possible to build in dimming capability, that would be fine. If not, it would be good to have the LEDs output a constant brightness over a pretty large voltage range up to 120VAC.
If anyone is interested in taking on the job, please let me know via PM so we can sort out price and details.
Thanks!