Took out the drill and did repairs to my 1:1 and 4:1 baluns. Made the holes wide enough and at the 3/4″ centers necessary to accept the banana terminal blocks. Sealed the interface between the case and the block with a flattened piece of Coax-Seal(tm) for water protection.
Looks better, and now the terminals won’t twist and break the internal wires. The closer terminal spacing but extra case spacing changed the impedance a little; now it rolls off around 20MHz instead of 25-ish MHz previously. Not sure why.
BTW, yes, those cores are wound with a pair of solid-core doorbell wire. Helluva lot cheaper than enameled magnet wire, and easily available at any hardware store.