Not disputing the insurance claims thing, just that Ford was not very diligent in stamping engines. Definitely had a lot of days off! Especially on certain lines of vehicles.
While there may be some out there, I don't think I've ever heard of anyone finding the VIN stamp on their original Bronco engines from the era. I know my '71 Bronco had it's original engine in it and did not have any other stamped numbers in it. Don't have the original for my '68 anymore, but I'll double check the Explorer engines I have, because by that time (late nineties) it must have been a more common practice even at Ford. I do have my original '79 400 sitting in the back of the truck however, so I'm definitely going to look for it!
I'll post a pic if I can find it somewhere on the block. Won't likely be able to see the one on my C6, but you never know.

Those numbering codes are "engineering numbers" and have nothing to do with either the date it was manufactured, OR the vehicle it was in.
When you look them up, most of those codes for engines indicate that they come from a car lineup, but as was mentioned before just because it was designed by and for the Fairlane/Torino team, or Mustang or whatever the result is, that does not mean that they were only used in that particular line of cars. As e150 said they did not design some engine families for specifically for trucks or cars. Ford used 351Windsors in both and they carried the same engineering number. Now maybe an odd one here or there, such as perhaps a 352(?) might have a "T" for the truck line, but most do not.
So when you see an engineering number with a "T" in the first sequence, it was originally to be used on a truck, but might still have found it's way to some cars. And vice versa...

And an engineering number might have been good for several years. Most of them were indeed used for at least two years or so. Which means that the OP's "D1OE - 6015 - AA" might have been found from, for example the '71, '72 and '73 model years. Not likely to still carry the "AA" suffix, as they often make subtle changes that give a different letter sequence, but would still carry the "D1OE" prefix, and always the same "6015" for that particular type of part.
I don't remember how the suffixes worked though. Was the first iteration just an "A" or was "AA" first? Dunno...

Your "D4DE" (don't remember seeing a "D" in the third position before, so not sure what group it was designed by) was designed for the '74 model year, but might have been used in other years. If you find the casting date that will likely be the only thing that will tell you if your engine is original to the vehicle.
If it was made after your truck, then it was a replacement at some point. If it was cast from about 20 to 60 days prior though, it's got a good chance of being original.

Paul

 

Thanks. I only mentioned the casting numbers as that’s what I was looking at, was looking for more info to find these stamps as I’ve never known them to be more than a myth until the 80s. Not worried about original on it, pulled it, stripped it and its sitting in the dirt not planned for use.