Slug Throwers: Technological Level Revision
Autopistol
Even if you assume that technological level four analogues are prototypes, they were mostly rather effective: the Luger was accurate if complicated, the Colt Semiautomatic tended to stop people dead in their tracks, and the Mauser was better than nothing.
The Fifties probably is the last time you really had anything revolutionary in gun design, and everything since then had been incremental improvements, with the autopistol probably equivalent to the Browning High Power, manufactured in the mid Thirties; at best technological level five.
Body Pistol
Taken as presented, rather than Bond's Walther Polizeipistole Kriminalmodell, maybe a composite carbon fibre receiver and barrel? That would certainly justify the technological level eight.
Revolver
You had them at technological level three, at the end of the sixteenth century; reloading seems a pain. Let's call it a prototype, with Samuel Colt's making the first viable mass produced models at technological level four.
Snub Pistol
I tend to think the human variant is likely to look closer to this, without a lot of the scifi frills.