Chris - I think your 40 is going to be like my 46. There are no "vin" numbers on them. There should be a metal tag on the right side of the cowel. Which from the numbers you gave I assume is still there. This is what the CHP will use to register your truck.
If you don't have the cowel tag the CHP will issue you a "blue tag" with a new ID number for your truck. This is what I had to do, even though I had the numbers off the ID plate (but no plate).
I did order a repo plate and stamped my numbers into it but the blue tag is still the registration number.
Good luck with your project, it sounds like a good one.
George