Welcome! To you and your bike. We are always pleased to learn of bikes re-surfacing, and meet their owners. You must have some experience with bikes and numbers to have come up with all the numbers. Please tell us about yourself and the condition of your bike.
The link Don provided is for the Interceptor forum (and, by default, all Enfield twins). As important a group as this one for you both. There is a member of that forum in Seattle and two more in Oregon. I am about 8hrs away, to the NE of you. You may also be interested in www.royalenfields.com
where you will see a blurb in the RH sidebar with Graham's email address: [email protected]
The Royal Enfield Owners Club in England has all the known surviving dispatch records for the past century or so, but I think you will find your bike is in a group whose dispatch records are missing. However, it may be possible to find the date your engine left the engine factory in Bradford-on-Avon or Upper Westwood (the B-o-A factory moved about then) on its way to Redditch to be assembled to the cycle parts. The numbers you provided are consistent with other survivors we have recorded, so it is probable your frame and engine left Redditch together. A few of us have been recording survivors as we find them. So far we have accounted for well over 1000 of the 4000 Interceptor 750's built. The numbers you have provided will help fill in the blanks in the missing registers, and helps us verify other machines.