Jeff,
My info was second hand so creadibility may be in question here, however from all the info supplied I'd assume the original engine was long gone. At the point in time it was listed on e-bay the seller belived it to be the original. Bid up to $6300. and reserve not met. pretty good money for what you have described.
The markings on the inside of the fenders are a neat find and may be the difinitive answer if it was an L36.
Here is the inside of my fenders markings.
