I would say it’s similar to a 618 but obviously older but not sure how much by?

I do have a 618 packed up somewhere I will have to find it.

I would say it is long like an adult rifle but obviously is very thin as these all seem to be much like a 618.

I will take a few more closer pics of sights and length and Hopefully Garvin may be able to post them here for me?

Just to clear one thing up, when I said rare I wasn’t thinking rare as worth a fortune or anything just that I’ve never seen another and I’ve owned one since the age of 5 and been shooting ever since, but bare in mind I don’t go to auctions or anything. Never seen one of these on here for sale or another site although always see 618’s and such

Thanks for any help so far