I pesonally dislike the makuni carbs that are on the indians. I took mine off and used a bing 1/15/27 carb. It mounted perfectly to the maifold. The reason why i dislike the makuni carb is its frustrating to hold the comression release and choke and give gas at the same time. I would rather have a manual choke on that moped.
If BK is offereing that carb for 25 bucks you should nab it if you dont mind the setup.
Also a good source for indian parts is bobs marine sales.