Last photo is most likely a Belgian Saloon pistol probably chambered in .22 rimfire though it might be a 9mm rimfire. Could be an obsolete calibre.
If its either of the first its a section 5 prohibited weapon & a nicking!
The pistol is cutaway at the breech end, there is no firing pin evident (from the age it would have been on the hammer, not floating) and the main spring is very rusted. I suspect it would class as a relic, possibly dug up in someone’s garden. Though I can’t examine it obviously, the outward signs are that it wouldn’t be section 5, but I appreciate we don’t know the calibre etc.
Looks like a 6mm Flobert parlour pistol, but the extractor is missing.