Donut tire size?

The spare donut that came with the '87 TC I bought a few months ago has a solid steel Ford rim/wheel, and brand new unused Goodyear 125-70R16 tire.    Sounds right, and approximately matches the diameter of OEM-spec full size wheels, but it doesn't fit in the donut well!  It's really difficult to remove/insert (can barely clear the decklid brackets) and once I do get it wedged in, the OEM trim cover doesn't fit right.

The donut that came with my '88 V6 is a 70R15.   Fits like a glove in both cars.   But of course it's smaller overall diameter than a full-size tire/wheel. 

For gits and shiggles I tried an 80R15 donut and of course, it doesn't fit in the donut well without a lot of grief and the same ill-fitting cover.

Seems obvious then that the 70r15 donut is the way to go, but I wanted to be sure the TC isn't a deviant in this respect?   Especially given the larger brakes, etc.   What size SHOULD a TC donut be?

The spare donut that came with the '87 TC I bought a few months ago has a solid steel Ford rim/wheel, and brand new unused Goodyear 125-70R16 tire.    Sounds right, and approximately matches the diameter of OEM-spec full size wheels, but it doesn't fit in the donut well!  It's really difficult to remove/insert (can barely clear the decklid brackets) and once I do get it wedged in, the OEM trim cover doesn't fit right.

The donut that came with my '88 V6 is a 70R15.   Fits like a glove in both cars.   But of course it's smaller overall diameter than a full-size tire/wheel. 

For gits and shiggles I tried an 80R15 donut and of course, it doesn't fit in the donut well without a lot of grief and the same ill-fitting cover.

Seems obvious then that the 70r15 donut is the way to go, but I wanted to be sure the TC isn't a deviant in this respect?   Especially given the larger brakes, etc.   What size SHOULD a TC donut be?

I just checked my '88 TC.  It has a Goodyear Convenience Spare.  The tire size for the spare is T125/70D16.  I am confident that it is the original spare, still looks brand new.  The car only has 38,000 miles on it.

The spare donut that came with the '87 TC I bought a few months ago has a solid steel Ford rim/wheel, and brand new unused Goodyear 125-70R16 tire.    Sounds right, and approximately matches the diameter of OEM-spec full size wheels, but it doesn't fit in the donut well!  It's really difficult to remove/insert (can barely clear the decklid brackets) and once I do get it wedged in, the OEM trim cover doesn't fit right.

The donut that came with my '88 V6 is a 70R15.   Fits like a glove in both cars.   But of course it's smaller overall diameter than a full-size tire/wheel. 

For gits and shiggles I tried an 80R15 donut and of course, it doesn't fit in the donut well without a lot of grief and the same ill-fitting cover.

Seems obvious then that the 70r15 donut is the way to go, but I wanted to be sure the TC isn't a deviant in this respect?   Especially given the larger brakes, etc.   What size SHOULD a TC donut be?

My 88 TC has a T125/70D16 Goodyear Convenience Spare tire.  It looks like the original that came with the car.

If you need a spare I have two. Nearly certain neither one has been on the road.