My manual says that it requires 754-0474 for the PTO?? I have the electric PTO in this mower
MTD did a part number rationalization some while ago so the 754 numbers all became 954 numbers.
A lot of these belts end up being silly sizes like the 754-0474 which is a 21/32" wide belt 101 & 29/32" long.
So a bit later on they get "superceeded" to a more popular size
The atermarket belt suppliers will change that to a standard sized belt in their listing so the same belt ends up as 5/8 x 101.
However with the vari drive belts thay are shallower than standard section belts which can end up touching the inner root of the pulley and not transmitt the power through the side which is how a V belt works.
If you go to
gates.com/all-search-tools/automotive-interchange-search-results and drop in the parts numbers you will get the nearest Gates equivalnet, some of which will be identical.
The gates belt number is a clickable link ( underlined ) and if you click on it , then click on the art number in the second window the specs of the belt get displayed.
I have not done it for your belt but if you do good change you will find all of the confusing different numbers are almost identical belts.
Getting my head around belts was by far the hardest part of entering the mower repair business.
Belt prices are a numbers thing, the more that get made the cheaper they become and then there are about 6 different cord fibers and unlimited numbers of variation in the size & placement of these chords followed by different rubber compounds and wrapping materials which is why a lot of the posters here who know who is who & what is what simply revert to recommending using original factory parts
