Honda dealers can still order them, they aren't cheap. Something slightly over $60.00.
GK says he is using a Dayco #17415 (also has 13A055 stamped on it) which he got at a auto parts store. It was discussed in another recent post: https://www.mopedarmy.com/forums/discuss/1/52353/52353/
You might try to get a dayco or use the number to cross-over to a different brand. All of the auto parts stores I attempted to match my belt at had significantly narrower measurements. I opted to order a OEM belt.