After reading the OP's original mods to his Sting..I decided to go about the exercise a little differently. My goal soundwise was to have a more ron wood/beck era tele sound. I have owned 3 different Fender tele SC basses in my career (as well as a 70's tele with HB) and all of them were different sounding instruments. I consider the current prices for these a joke, though I play basses, and don't collect them as commodities. So- onwards and downwards.
I started with a CIJ Fender 51P RI. I believe I am the 3rd, maybe 4th owner. When I bought it here on TB, the bass had a Lindy Fralin side /side hb sc., and a modern fender string through/top loader option bridge. It had been poorly shielded, had the wrong bridge cover ashtray, and somewhere along the line, somebody had taken off the sharp corner on the lower bout, in an attempt to alleviate the square edge of the slab. It was the hideous yellow color.
I played the bass a bit as is-the Fralin sounded good, no noise..but it didn't sound like a SC tele/51..more like a standard Pbass. I have a standard pbass, and don't need another. So- off to the custom shop at SD, where MJ provided one of their vertically stacked sc's. Like the original OP, I had it made on a slightly smaller base, so that it would fit. however (again like the OP) I had my luthier deepen the hole, as the 4 wire cable is shielded and thicker. He dropped it down about 1/4". I went through a lot of ideas for wiring it, and am still experimenting, but as is, the PU can be used as a SC or as a vertically stck HB, it's on a push/pull (the tone control) . Now I have both..a quiet HB or the fabulous spikey SC sound. My luthier also reshielded the control cavity..and did a little trick I'll share. After playing these basses for a while over the years, I had come to the conclusion that the pickup cover ashtray is a GOOD thing- it prevents me from using the pu as a thumbrest, no big deal on a PBASS, but the 1st time you rip the top bobbin off in the middle of a set..and 2) resting your hand on the ashtray sets up a perfect playing position for John Entwistle over-the neck playing. What my luthier did was to run a wire form the shielding in the cavity to the ashtray..there's already a wire like that to the bridge, right?..so when I am in SC mode, I can reduce to the bzzz to almost zero simply by touching the ashtray.
I have also gone back to using the original 2 saddle steel bridge. It sounds better to me, and after years of tweaking these basses, as well as original NJ Dano's with the wooden shim bridge..it's possible to intonate this bass with the org bridge. really.
I had the bass refinned in white, with a white pickguard..looks like it should now. Took the gloss off the neck, using the typical TB method of pad sanding..the necks on these are really good, a lot better than any of the 60's Tele I have owned. For about 1/4 the price of a 60's tele I have a great sounding, more versatile bass that has become my daily player.