There is currently an HO ICH B&M Alco C-628 posted on ebay. I realize that there isn’t a prototype for every model created, and I believe this is the case. I don’t ever recall the B&M owning any C-628’s but I could be wrong…
They didn’t have any - according to this source:
http://www.trainnet.org/Libraries/Lib003/B_M.TXT
Looks a bit odd to see that scheme on that loco too… [:O]