The Flying Fish's transmission does have nearly identical dimensions and could probably work in a pinch, but it happens to be the weak point of that particular model... I would recommend the already-mentioned transmission if its within the budget.
The HSP transmission is cheap though, for less than a fifth the cost it can't hurt to try...
Gonna infodump in case you do go this route...
See pin 02195? That's a hardened steel, 2mm x 8mm pin which is never included when you buy the gear or transmission sets separately. Here's what gear 02041 looks like:
Notice the hole in that "ramp" where the pin should go. Even the whole transmissions are sold without that pin, which makes the omission even harder to notice.
I had to figure out the hard way why my replacement transmissions were failing. Without that pin, it'll shift, but the metal "claw" (02045 in the diagram) is grabbing the plastic of the gear, and wears it out after a few shifts. I improvised that pin from one of the wheel-hex pins, I had to grind it down a little since those are 2x10mm, and then it was getting pulled out of position in the gear by the shift claw, SO, I held it vise grips and heated up the end until it glowed red-hot to anneal it, and then pounded it with a hammer until the end "mushroomed" slightly. The end held in the vise grips seems to dump heat into them quickly enough not to lose its hardening. I pressed it in from the back, so the mushroom head was on the opposite side shown above. This arrangement finally proved reliable, lasting until the claw wore out...
So, yeah, I recommend that fancier transmission even though I haven't tried it myself, it looks like it uses an actual friction pad & bell clutch which should be a lot more reliable than the pin-and-claw.
