A ratchet that skips or slips under load has worn its gear and pawls, and the repair kit is the answer: matched by brand and drive size, quarter, three eighth or half inch, each kit carries the gear, pawls and springs of its mechanism, so the Siegen quarter inch, the Sealey and the Sykes Pickavant handles are rebuilt at the bench in minutes for a fraction of replacement.
The torque wrench question gets the honest version here: a repair kit restores the ratchet mechanism, and the Sykes Pickavant kits serve their wrenches by model, but accuracy is a separate matter, and a torque wrench that has been dropped or reads doubtfully needs checking against a known standard, not just new pawls. The kit fixes the click and the drive; it does not certify the number the wrench was bought for.
The extension bar families run in coded ranges: XP1000 VDE insulated bars by drive and length, quarter inch from 50 to 150mm, three eighth to 155mm and half inch to 255mm, for live-side electrical work, with impact-rated extension bars beside them for the gun, because a chrome bar on an impact wrench is the wrong metal in the wrong place.
The repair layer runs deeper than ratchets: metric thread insert refills in M5, M6, M10 and M12 packs restore stripped threads, hook and pick sets, Knipex insulating clamps, drill pump adaptors and the drain blaster force cup serve their tools, and socket rails and clips keep the socketry itself in order. Brand and drive typed into search find the kit, and a photo of the stripped mechanism over WhatsApp on 07754288583 names it where the markings have worn.