If you've ever tried fitting a GK2/3 pickup to a Strat there's a fair chance you've cursed Roland for not including a DVD of Valerie Singleton making sense of the Blue Peter style assortment of bits of plastic, screws, washers, sticky tape, sticky pads and so on that constitute the official mounting kit.
Peteroni's kit consists of a machined steel mounting plate, a pair of over-length pickguard mounting screws and a substantial quantitiy of washers. The pickup is mounted by sandwiching it between the pickguard and the mounting plate, which latter is secured in place with a pair of screws - the supplied over-length ones, which replace the existing two pickguard mounting screws either side of the bridge plate. The washers come in to play to raise the mounting points of the bracket to slightly less than the height of the pickup, ensuring that once the screws are tightened the mounting plate grips the pickup into place.
The pickup height is adjusted using Roland's supplied shims, with a corresponding adjustment in the number of spacer washers used at the mounting points. All very simple (OK, handling the washers can be fiddly but I managed to get a couple of small stacks of them into place without either swearing or resorting to Peteroni's suggested superglue). The holes for the mounting screws are in fact slots and there's some intentional play in the slot for the pickup so tweaking the pickup's position is simple - then just tighten up the screws and you're done.
I have to say I'm well pleased with this piece of kit. Yes, it's very much a niche product but it's an elegant, inexpensive solution to a potentially frustrating problem, it arrived quickly once ordered and it came with excellent instructions (and enough washers to kick-start a pretty major Mechano project). Very cool, thanks Mr P :)