what I have so far , this version calls for a red tipped spinner. I have never had to tape off a spinner , this is scaring me

Depending on how you need a red tip, either use Tamiya curve tape or Eduard mask.
https://www.scalemates.com/kits/eduard-jx502-spinner-spirals--116557
Hope this helps.
Calculate the diameter and cut a circle in a piece of stiff paper, or thin cardboard, and slip it over the spinner so that the amount of spinner tip left exposed is the area you wish to paint. It should look like a little sombrero! Secure in place with a couple of small pieces of tape. Spray.
Spray the other colour first, to seal the gap between the mask and the spinner.
Many, many years ago I read about a tip that I tried, (FSM?) with a modicum of success.
Punch a circle in cellophane - the stretchy kind. The hole should be smaller than it needs to be. Stretch it down over the spinner until it’s where it needs to be, and make adjustments to it until it’s right. The advantage is that the cellophane makes a pretty good seal. The disadvantage is that it depends on your MK I eyeball to get it right.
I’ve had better success with the “sombrero” technique above, except I do it by punching a circle out of styrene. Then I chamfer the edge so that when I place it on the spinner the edge of the mask actually meets the spinner.
If none of the other options works out there is another way. Imagine a lathe. I put the spinner on the end of a drill bit using a hefty chunk of Blutac to hold it in place. On the lowest possible spin setting, with the drill clamped, and with a fairly steady hand, I held a small paintbrush loaded with paint to the tip of the spinner and gradually worked back to the necessary line. From memory it took a couple of coats but that would likely be necessary whatever method.
I wonder how they did it on the real plane? Let the engine run and a mechanic approaches with a brush on a broomstick?
That’s funny!
Spinners were probably not all painted perfectly, as this original shows. Nor did they need to be. However, such intentional imperfections are difficult to pull off in 1/32 or smaller without looking amateurish.
The above photo also shows that many spinners were made of more than one part, so that it would be relatively easy to paint “just the tip.”
that is interesting