I'm guessing Resin Ranger has shot his load and isn't making kits any more. He also produced the speedboat shuttle kit, which I stupidly never got around to buying. Resin Ranger is no longer listed at fed Models.
I am the one who was responsible for making the patterns for the Galileo and the Speedboat shuttles. They were retired but are due to make a comeback by popular demand under the Alliance Models banner thru Federation Models. Not sure on the availability because of Tracy's recent move to Florida but keep an eye out for them if your still interested. I am also the one responsible for the 1/72 scale Galileo that made it's debut at WF.
Oddly, the most accurate version of the O.S. shuttlecraft I've come across is the 8" pewter "paperweight" put out by the Franklin Mint in the mid 90's. They got it right down to the last detail -- and I should know; I grew up a few doors down from a guy who, for a time, owned the full-scale shuttlecraft built by A.M.T. for the series. From 1974 until some time in the early 80's, the Galileo sat rusting in this fellow's front yard. As kids we used it as a clubhouse; in highschool we used it for other, ah, less innocent purposes.
My neighbor eventually sold the shuttle (it was in terrible shape, the elements having taken their toll over the years), and I lost track of it's whereabouts. I seem to recall being told that someone had restored it, but I can't be certain. In any case, I've always been particularly nostolgic when it comes to this ship, and would love to see someone produce a truly accurate model. Until then, the Frankling Mint version will have to suffice.