1810-0146 replacement

[tomcircuit]

Hello! I recently acquired an HP-55. After some cleanup and TLC, reassembly, and a new battery pack it's working pretty well now, except for one issue - no decimal points will illuminate. All other display aspects are fine; the segments & digits are all well behaved. I did some reading up (ClassicNotes.PDF) and suspect the root cause is an open coil in the 1810-0146 quad coil pack. All of the coils are low ohms to common except for the decimal point coil.

Other than taking a 1810-0146 from a 'donor' calculator, two solutions come to mind:
1) solder a small fixed 68uH inductor across the open coil in the pack, or
2) make a replacement "pack" from four small fixed inductors (1x 68uH, 3x 130uH)

Has anyone else faced this issue? I'd love to hear how you solved it.

-tom