Here's my kitbash with the Space Tracker sculpt. Since his noggin is so huge, I thought the best way to downplay it was to just make everything else slightly oversized: Hoth Bespin jacket, elongated neck joint, longer TT arms and legs and NewLine German boots.
Yeah, I did the same thing - made the overall figure 12 1/4" tall rather than straight 12" (HF is a bit over 6' tall anyway) and added the bulky coat. Here's a couple of quickie snaps of the sculpt on an ESB set-up, but with the ROTJ hasbro trenchcoat over. I think the head matches ROTJ Han better than ESB Han - it seems to old for ESB to me. And I wish I could see past that cartoon chin/jawline this sculpt has - tilting the head down as I've done in these pics helps though.