They do make a "black out" shade that fits the Monterey 270. I have a friend who had a Cruisers Yacht 320 and it came with the round black out shade. When he traded up to a 420, he gave me the shade which fits perfectly in my 270 (same hatch). It really makes it nice when sleeping in the front v-birth!
I am not sure if it is something that Bomar would have or maybe something you could order from a Cruisers Yacht dealer, but I have never found one online available for sale.
Eric