Making some progress.
The proto boards arrived from pcbcart.com, everything looks fine (except for the garbage picture, the lighting makes it look like a pretty poorly made board... but I didn't feel like taking another one).

And fully populated:

Front showing 4PDT switch location:

For the inductors, I wound up some rm8 cores. For the 1H low frequency inductor, I used N48 630, ~1,300 turns. For the 100mh mid band, I used N48 400, ~500 turns.
This is how everything will (in theory) fit nicely in a 500 series. Note that the Harrison Ford Filter PCB will actually be upside down when all comes together.

It looks like it will be a bit too tight for comfort on overall width if I use the pushbutton switch on the Harrison Ford Filter PCB, so I decided to wire a mini DPDT toggle switch off board for this function. Here's the overall fit once everything is populated. (I haven't drilled the L-bracket yet, hence why it's backwards.)

From the looks of things, the pot and switch locations should provide a pretty usable face plate configuration.

Now I just need to finish wiring everything up and test it out. Hopefully it sounds ok and nothing catches fire.
That's all for now, more to come soon!
Thanks,
Keith