I spoke with John about a year and a half ago regarding backdating his kit to a class 56 or 60. He said that the frames of the early stuff were heavily modified into what later became class C-16. (I haven't compared photos yet). He also told me he has actually had more requests for the early version than the modern stuff but had no plans to do an early version. He told me that domes, pumps etc will be interchangable but he has no plans on doing 4 panel cabs etc. (remember this is 18 months ago and things may have changed) If anybody does a pre 1900 backdate to one of the SJ kits please post photos for the rest of us early foamers!