Hi,
It looks to me like the base plate in 7495 is the same as that in set 3125 (
30 89 7990 - Rock base with bridge). This baseplate has holes that will allow combination with other PM rocks, but it is molded in one solid piece.
I'm not so keen on 7495 myself: the use of the knights in the new liveries is good, but why include a cannon that belongs on the deck of a pirate ship when they've created new, more medieval-looking guns for the new knights theme? At least the old 3125 set had a slightly wider range of parts, like the blacksmith's tools.
Hmm, I seem to have gotten up on the grumpy side of the bed this morning...
Anyway, hopes this helps,
AndrewL