I recently got my first bike. Got a 2006 Boulevard M50. It seems like a great first bike so far. I'm a bigger guy, 6'1" and 300lbs and I feel comfortable on the bike. One thing I go want to change is to swap the passenger foot pegs for floorboards just for a little more passenger comfort. But, I am having a tough time finding floorboards for it. I have found floorboards for the C90 and and even the C50. My questions are:

Are accessory parts like floorboards for the most part interchangeable? Like would passenger floorboards for a C50 or C90 fit on the M50?

And, where are good places to find parts like that? Seems a bit hit or miss on the few sites I've cheeked.