Here's an M23, M17, & M15 side-by-side from the Front and Back. The M23 is Walkabout owned by Nick Honodel, the M17 is Bellerin owned by Gary Valetti, and the M15 is Seas the Day owned by Doug Kelch. (Photos courtesy of Doug Kelch)
Randy Sommerfeld's M17, No Worries --- here's another look
Hank Kwant's M15, Hull #462
Abbey Gura's M15 Hull #466
Randy Graves' M15 Hull #407 side view , interior , and cockpit.
Greg Hahn's M17, Spoonful
John Edwards' M17, Miss T
Don Haas' M15, Dream Catcher at sunset
A "photo" of a Montgomery 23!