Mito, There is lots of help available. First step is to understand exactly what you have, and the serial numbers will get to the point. If you post the engine and frame numbers here, we can help. Or you can go straight to the well, the Royal Enfield Owners Club in England. Their chairman, Graham Scarth, will do a quick look-up at no cost. (Paper dating certificates from the club are for a fee.) [email protected]
Or go to Royal Enfields.com and see the blurb in the right sidebar. Graham prefers to have photos of the engine and frame numbers to ensure there is no miscommunication. You can help him complete the records by supplying the gearbox number that is stamped on the front of the crankcase too. The actual number of the gearbox is on the top of the main case, near the joint with the covers on the right side of the bike. There are no security concerns posting the numbers. The full range is known and publicized; we just want to know where to fit these bikes in the sequence.
Engine number with all letter prefixes and any suffixes are on the left side of the crankcase, just below the cylinder. Enfield frame number stamped into the left side of the headstock, not the raised casting number on the right. Not sure about the Clymer/Italjet number location.
There are a couple of competent and knowledgeable enthusiasts in Taranaki who may know of other help closer to you.