[jrblasde]

I've ordered the components. I may have found the most elegant breakthrough yet--a 22 µH coupled, shielded inductor. See the attached data sheet. If this is really what I think it will be, then I can do this entire design on one flat PCB the size of old the 3/4" x 3/4" IF can--and without the can for a shield!

I took Chas' advice, and looked up the inter-electrode capacitance of the primary and secondary tubes. The plate capacitance of the 14F8 on the primary side is 1.4 pF, and the grid capacitance of the 6BJ6 on the secondary side is 4.5 pF. So I have bought some different fixed resistors to use for testing. If the shielding on the coupled inductors proves to be adequate enough, I can bypass any added parasitic capacitance introduced by placing the old shield over top of it all.

Just for backup, I still bought two 22 µH inductors with radial leads.