The Gadget Man. Click Rush, the Gadget Man, was created by Lester Dent and appeared in Crime Busters from 1937 to 1938. Rush was a tall, lean, strong young man with brown hair and eyes. (Brown was his favorite color; he usually dressed all in brown.) Rush was an amateur investigator who invented gadgets towards this end. He'd come to the "big city" with the "notion of selling super-modern, crook-catching gadgets to the police." After the cops laughed him out of the station house he went out on his own.
Well, okay. He was prompted by a talking toad: "Bufa, of the species Bufonidae, which feeds on snails, slugs, insects, and such undesirable things....(I'm) eager to hire an expert private detective to investigate crimes I think need solving." The toad succeeds in convincing Click to solve crime (the $10,000 fee for each crime helped, too.) but proved to be an only average boss, enjoying giving Click the razz and showing a mean sense of humour.
Among Rush's gadgets include a portable x-ray device, phone-tapping equipment, a bulletproof vest, a repeating hypodermic needle he used to deliver a knockout drug; exploding matches; knockout gas vials; containers of liquefied tear gas; and a number of other such things.
A mad inventor and techno-detective of the 1930s who believed himself to be the employee of a toad. I suspect the toad to be the kind depraved people lick.
Anyway. Wrap your brains around that one.
Your task, as ever, is to re-invent that into something a 21st Century audience could enjoy.