So I just completed this thanks to Raventai's homework! And while you are correct there are 2 different types of waterproof 2.3mm terminals, they appear to fit in 'each others' spot!
So first off I pulled a total of 3 complete dual filaments from the wrecking yard Celicas, so I would have extra terminals, (so I wouldn't have to buy new ones!). However I changed my mind on splitting my wiring. Since I have my blinkers in my ARB bumper set up as dual filaments
HERE as well, I simply unplugged my 2 wire side marker, added the blinker terminal in the place of the empty terminal, and plugged the new Celica light in. I didn't think I needed 3 blinkers, but you could easily accomplish this if you wanted. I slid out some of the extra Celica terminals and they do fit our holes, (now, that just don't sound right!), and make a solid connection.
Don't know what the factory service tool is but I just used an eyeglass screw driver to prop the terminals out, a bit tricky but just takes time. The 80's do have little plastic protector on each end of our plug that need to be slid out prior to removing the terminals, (pic below), but besides that the Celica & 80 plugs are very similar.
I think I had to change one of the terminals meaning the configuration was off from our factory location to the Celica's, (i.e. the blinker would have been the dim one and the marker would have been the bright one!) Hope that's as clear as mud!
Here's some pics and a video to show ARB & marker dual filaments...
1st pic - side by side comparison
2nd pic - before pic
3rd pic - complete. the tapped over wire is the factory ground from the blinker, I basically just unplugged both terminals from the blinker. If you wanted to retain your factory blinker you could simply use one of the extra terminals and wires from your 3rd wrecking yard light, (which is why I originally grabbed 3, just changed my mind and didn't want the 3rd blinker).
YouTube - ARB blinker & side marker, both dual filament
LINK to my ARB dual filament mod