https://myronsmopeds.com/2020/12/vespa-speed-versions/
so from what i can cross reference, appears 20 mph had tiny carb 10 sha. 25 n 30 had 12 sha both with 49 main.
Everthing elese the same except thme exhaust pipe. read the numbers and check... Or get her running and test ride. I would never buy a non runner for 500 because a running moped is priceless. Dont get me wrong but i have paid 500 for non runners but tyet were something special.