I had a pump crosman similar to the 760 wood stock and all it had a rifled barrel! It burnt in a house fire , I’ve looked for on ever since and have never seen one exactly like it !
There may be a number 66 or 7 on the front cap that the pump lever pivots on , many times they are painted over. maybe a piece of paper and pencil rub would reveal it ? PS I do like the head to heads, I may just do some myself if I get motivated !