I have a Savage model 99 takedown, in 30-30, made in 1920. It was my grandfather's and has seen heavy use in the woods of Maine. I know the barrel and butt stock have been replaced due to wear. It has the shotgun butt plate but I'm not sure which exact model it is. It also has a cartridge counter and straight stock. My main difficulty is with the additional .410 barrel. It has a screw that looks like it should anchor in the fore stock but it doesn't look right. I could be missing a part. Does anyone have any info that might help?