Sorry just re read your post that you've determined that it's a sideoiler already. So the early two bolt motor mount does not apply. Casting numbers are your best bet from the block, heads, intake. Carb numbers, distributor numbers all these are there and will help you determine how original it is. They will be hard to see in the cobra though but with some patience you'll find them. It's the date code that is under the oil filter pad and if you can see it you'll know the casting date. Everything should be within a year on casting number and a few months on the date codes if it's all original or someone took the time to collect all the right date coded parts. Or it could be a festive blend of whatever. Cobra guys are pretty fussy though so I doubt it's been hodge podged but you never know. If you can give me some numbers I can help you ID them. G.