Making an adapter for HC46/U crystals to the FT-234 socket is not difficult --
If you have an old octal tube, break the base but save the pins - they fit into the crystal socket holes.
Get a strip of 5 or more machine pin sockets with 0.1 inch spacing - a straight piece of a DIP socket will do. The leads of the HC-49 crystal are spaced 0.2 inches.
Solder the pins from the octal socket to the 1st and 5th pins of the SIP strip and solder between pins 1 and 2 and also between pins 4 and 5. The HC46/U crystal leads plug into pins 2 and 4 of the SIP strip.

73,
Don W3FPR