Thanks Alibi.
For Holmes the recipe is 16k head (of course) on a TTL WWII body with the long HT T-800 footpegs. The hands are from store-rooms. I'm pretty sure they are recasts of HT hands, but they are much smaller so they are more in scale with the head.
His outfit is a CrazyOwners white shirt with the cuff buttons replaced with black buttons to simulate cufflinks. The tie is black ribbon and tacky glue. Waistcoat is Battlegear Toys. The watch-chain is custom from a craft store necklace. Because the waistcoat pockets and buttonholes are real, it is anchored on one side with a pocket-knife, goes through the button hole, and then is attached to a watch in the other pocket. The fob is a 1/6 brass button attached to the chain with a bit of wire. His frock coat is Sideshow. His trousers are from the Drastic Plastic FDR figure with the cuffs let out. The boots are Toy City WWII Russian boots. The violin is from eBay with the chin rest removed.
Watson is 16k head on a TTL WWII body with regular footpegs and regular HT hands. His outfit is the Mattel Henry Higgins suit. The only change I made was replacing the original bead buttons with regular buttons from a Dragon coat. His waistcoat doesn't have real pockets or buttonholes so the watch chain is sewed in place. His fob is made the same way as Holmes's, but the button is a different style. His boots are DID WWII American army boots.
So most of it is off the shelf stuff with a minimal amount of sewing and fabrication to give at least a superficial appearance of being screen accurate. All I know is I'm very happy with them!