Got the tape and ready to install. The original B&B city/gravity feed water inlet (it is rectangle with both inlets for city and gravity feed water) had a solid brass connector with 1/2" MPT and Keystone used a 1/2" plastic compression fitting that mates with a 1/2" braided hose for the city water inlet.
Noted that the "upgraded" new B&B replacement water inlet has a plastic 1/2" MPT connector and the compression fitting just won't work with it as the surface end of the plastic fitting isn't flat enough and the compression gasket just smooshes inside. Went to the hardware and bought a regular 1/2" MPT to 1/2 barbed hose adapter. Couldn't get it to stop leaking with teflon tape. Couldn't get it to stop leaking with pipe thread compound. Couldn't get it to stop leaking with Permatex Hylomar union seal compound. The new adapter is now being epoxied onto the plastic fitting. They do still sell the old style part with the BRASS 1/2" MPT fitting and I just bought one (just in case the epoxy doesn't work). Plastic kind of sucks. I bought eBay item:
This assembly is identical to the original (plastic fitting) one purchased but has a brass 1/2" MPT fitting for city water:
https://www.ebay.com/i/200927737691?chn=ps