Weren't they actually a medium frame, smaller than the military .577/450's and larger than the small Cadets and .22 target guns? Navy Arms also sold 14 gauge Martini shotgun (maybe the same gun?), ex-police guns from somewhere in the British Empire, that had an odd double firing pin that stymied a lot of Bubbas who wanted to convert them to sporting rifles.
Navy Arms had their operation in WVA down the road from where I lived back in the day. Lots of neat stuff was sold in their storefront that was uncataloged. I remember a big bin of those Martini actions in varying states of usefulness.
