Hiya, I have tried changing pickups in a Maverick F1 w/o the rings before and let me tell you it's not fun. The pickups fitted were SD JB/Jazz combo and they didnt fit straight away. First of all, the pickup width (not length) was too fat so I did a bit of sanding to make em fit in. The screw that screws the pickup into the body were too big for the holes in the SD pups, which I think are the standard size. I went to some DIY stores but couldn't find correctly sized screws so in the end I just made the holes bigger thus sacrificing the chance to fit them in any non direct mount guitars :( . It's kinda scary too directly mounting pickups I kept worrying that the screws will come through at the back of the guitar lol. The final pain is the wiring, I was very inexperienced with switching pups back then, and the unusual shape of the control cavity made it very dificult to put everything back in the right place. In the end I ended up chopping quite a bit of wires off but I wish now that I hadn't done that. My advice is if you're inexperienced, take it to a guitar tech. Hope that helps. :)
