Paul, As I mentioned, my Orion .8x FR looks identical to your FF. On my Nikon, I use 2 different T adapters, see attached pics. Both are just attachment adapters. No additional spacing. On the left threads are 42mm (std),,on the right is a “wide” thread 48mm. I use the wide one with the FR. The wider thread helps prevent vignetting. With the wide one I also need one 2 inch extension tube. The 42mm is used with no FR.
Since your T2 adapter has some extension built in, perhaps a smaller additional extension is required, or a T ring (probably like my wide), with no extension, plus one 2 inch extension. Extension tube kits are available with multiple lengths, The pic with the camera shows my setup. I would just screw the ext tube on to the telescope.
Hope this helps. Harry
Vero Beach, FL
Mounts: ES iExos 100-PMC Eight
Scopes: ES ED80CF, ES AR102, Meade ETX 90 EC (Deforked)
Guide: ZWO 30mm Mini, ZWO ASI120MM-Mini
Software: ASIair Pro, iPad Pro, MacOS, Starry Sky Stacker, Affinity Photo, Lightroom, SkySafari Plus
Cameras: Nikon D600, D5500
Misc: ES USB Power Bank, Rigel QuikFinder, 0.8x Focal Reducer
Filters: Optolong L-Pro, L-eNhance