I have a 7.62x39 Russian or "Enfield K" conversion on order for an old No.4 Mk1* Enfield from them as well.
Parts to be converted were shipped to, and received by SIA in July, 2012. I haven't gotten my kit yet and no status request has been given a good response.
I'm just going to wait until the kit arrives and finish the project.
Would I do business with them again? Probably not.
Was I expecting the kit to be shipped to me within a specified period of time? No I wasn't.
Because gunsmiths and custom parts take time to build/modify/get turned around. And because no definite time frame was offered or inferred.
It's a project for the heck of it and not a needed piece of hardware.
NRA Chief Range Safety Officer, Home Firearms Safety, Pistol and Rifle Instructor
"There are three classes of people: those who see, those who see when they are shown, those who do not see."
Leonardo da Vinci