Aliexpress has stuff that doesn't appear to have ISO specs in various multi-sprocket thread-on freewheels. It takes quite a while to look thru the stuff because their search REALLY sucks, so you usually have to use a google search of their site to find things, often by reverse-image searches rather than text (because words are often misspelled or completely wrong ones are used for what something actually is, etc).
But it might be worth looking, if you really need one--just make sure that the specs provided for a given freewheel are what it actually is, and that this matches what you have on your hub.
(I just spent a lot of time, the last several days, trying to find an ISO 18T singlespeed freewheel with reliably given actual ISO specs, *and* splines or slots for common removal tools (most of them dont' have any way to remove it other than disassembling it, which is ridiculous because it doesn't take much to add (to the design) the metal ring to host the slots and then add the slots (simple enough manufacturing processes compared to the rest of making the whole part)).
BTW--since ISO thread-on freewheels/hubs are sized and threaded the same as the same diameter BB (bottom bracket) parts, you can use the one part to test fit and verify dimensions of the other, if you don't happen to have the proper part to mate with it and need to know what it is to go buy that part.
