Great looking bird! A fellow here in Mid-Missouri is building a SR-71 that will be as follows:

"...it's a SR-71 Blackbird, also known as the Sled. This beastie will be 1/8 scale, which will put the final size at exactly 13 feet long, and 2 inches short of a 7 foot wingspan. Final dry weight I'm shooting for, is 45 lbs, and is to be powered by 2 AMT Mercuries."

I think he is building the molds and everything by hand, check it out: http://www.mmrca.org/lance/