[christge9]

For anyone interested, this was resolved using 16T of #29 wound around a cardboard form (shaped to the cabinet opening). I secured the windings with varnish to brown packing paper, which looked authentic.

Measured 3.1ohms, 0.227mH; which was right in the middle of what the resonance calculator determined (using ends of tuning cap range).

Performance was great, and even worked well without an external antenna.