ISO headshell for Systemdek IIX / Profile tone arm

I have a spare cartridge I'd like to use with my early-eighties Systemdek IIX turntable by keeping it (the cartridge) in a separate (and, preferably, identical to the one already attached to the tone arm) headshell, so that ideally I could swap the two headshells in and out of the tone arm easily and whenever I wanted.

The problem of course is finding an indentical (or similar) headshell. The Systemdek came with -- as, I've gathered, most Systemdeks did -- a Profile tone arm.

My quesiton to any and all: where might I find a headshell that will fill the bill?