Haha! I began the exact same figure last summer but never completed him yet. I dismantled a spare Smolly and bought a broken Jack Sparrow off eBay for some of the accessories. If you've got a Clifford lying around, you could use his dreads.
I should have enough pieces left over of Smolly to combine with a series one Kermit and also make a shirtless Smollet with the Benjamina tattoo. Need to have someone sew me a little cloth shirt for him to wear.
And speaking of POTC figures being used for Muppet-related customs, I also bought a Barbossa on clearance from the fourth film. I plan to repaint him to be Long John from the end of MTI... he's got the fancy coat, the crutch, he's perfect.
I even thought about replacing the head with a Tim Curry sculpt, possibly from a Rocky Horror Frank N. Furter figure.
Alex