Unfortunately, AliExpress search isn't what it used to be. It really takes some effort to find things, even with AliTools assistance. 

The good news is that this motor is claimed to be 24mm and comes with the cable terminations I'm looking for, and it comes in over £1 less than the 17HS4023 motors I found, thus £31 before VAT. It's also allegedly 0.24Ncm, which is twice the 0.13-0.14Ncm of the 17HS4023 motors.

The bad news is that there must be 2 different motor drawings on the listing, and the motor in the image is like the superposition of them:

Continuing to look through Reverse Image Search, it seems the seller also has 3pc and 5pc listings, the latter has both an image of a worker holding the motor and a drawing that seems to line up with all the claims: