Changing Blacktops for Filtertrons - surround not compatible

Fuengi

Can anyone help me source the correct pickup surround so I can replace the Blacktops in my Gretsch 5420 with Mojotrons?

The surround for the Blacktops has three screws which the pickup lugs attach to and are adjusted. The surrounds are attached to the body with four screws. The pickups can be adjusted vertically through the surround to move the pickup closer to the strings. 

The Mojotrons don't have lugs, and have two screws to connect to the surround. I'm not sure the Mojotrons can sit surface on top of a surround and clear below the strings? 

Thanks in advance, I'm struggling!

Corvus

The Mojos are direct-mount to the wood/body via woodscrews - that's the trad Filtertron arrangement. They don't mount on or hang from surrounds, those are purely cosmetic things in this setup - you can take 'em off and the pickup stays put.

One way people do it is add a small wood bar under the pickup (lolly sticks..) which is fixed in place by the pickup's two through-screws.
The bezel screw at the single screw end is threaded through the stick/bar, so it still acts as a height adjuster.
The other end with the paired screws, add the TVJ adaptor to the stick. That takes a single screw to the paired BT setup -
https://tvjones.com/dual-screw-mount-adaptor
(Making one of those wouldn't be too hard, to save the post wait).

Have a look at post #19 in this thread for a pic it should be clear what the deal is.

An alternative is adding wood to the guitar, inside the body at the pickup rout ends, so the through-mount screws have a place to go into.
And replace the BT surrounds with trad surrounds - but check these are the same size/screw positions. The old model 5420s weren't but yours do look like more like the trad surround sizes.

ICBM

Are the actual pickups exactly the same size, including the outer dimensions and polepiece spacing? If so there's another solution if you're not planning on selling the Blacktops - remove their baseplates and mount the Filtertrons on them, then they can be put back in the existing surrounds. You could attach them either using the four coil screws, or drill the baseplates and use long bolts and nuts through the normal Filtertron mounting holes.

Fuengi

ICBM said:

Are the actual pickups exactly the same size, including the outer dimensions and polepiece spacing? If so there's another solution if you're not planning on selling the Blacktops - remove their baseplates and mount the Filtertrons on them, then they can be put back in the existing surrounds. You could attach them either using the four coil screws, or drill the baseplates and use long bolts and nuts through the normal Filtertron mounting holes.

The base plates are soldered to the pickups, I'm a bit reluctant to de-solder them as I might put them back in at some point. 

A bit of ply below the pickup sounds like a plan, with new surrounds. 

Cirrus

Since you've got a good answer, I'll just chime in to note your good taste in putting those pickups in amongst the gold hardware of the 5420 - I did the same with my 5422 and think it looks way classier