Question about spare tire size

[JaguarBrad]

Hello all,
Just joined the club and forum.
I am doing a restoration of a series 1 FHC and first thing I need is wheels and tires.
The car will be painted in 3-4 months, and then put on its wheels and shipped to me.
Leaning toward painted 6" Borrani with Michelin 185/70-15.
This seems a great combo based on the forum.
We have terrific mountain roads here so want it to be lively.
Can try 205 in the future maybe and compare.

But my questions is, although covered in past posts, about the spare.
I would like to have spare same size, but un-clear if a 185 will fit under cover on 6".
Unsure if those whom say will not fit are running 205's.

If only a 5" will fit(or 5.5), will get a lower-cost/used wheel.
Do not want the tire cover to bulge.
Feed back is appreciated,
Brad