In an instance of shocking stupidity, I went and did the same thing all over again (ie: Purchased a D&D figure off eBay wiithout a proper idea of the scale).
In this instance, I was looking for alternate Flesh Construct figures for Dr. McMourning to create in-game, and I came accross this fellow:
I thought: "There's no way that guy can be too large to fit comfortably on a 40mm base, right...?"
Oops!
"Ya better be nice to me, or my big brudder will mess ya up...!"
Of course, if one wanted to mount the Bersek Flesh Golem on a big wood chip rock, you could probably squeeze him onto a 40mm base OK, I've just been wanting to use the same Fenris resin bases for all of my McMourning figures.
Oh well, live and (don't) learn, apparently...