How to go about it?

I can’t use the same technique for the canopies I had used because they have faintly molded frames.

I have tried using masking tape but after an hour or so I called it a day when I noticed the tape I was using was leaving glue residue and was smearing the clear parts.

I found another technique which I had used in the 70s.

https://finescale.com/how-to/articles/2018/06/builder-basics-3-techniques-for-masking-canopies

…a desire for very fine edges makes adhesive-backed foil a good choice. Aluminum or gold foil is less reflective than others, which makes it easier to see. Apply a little more than you need and burnish it down.

I had Elmer’s Spray glue and lots of aluminum foil. I tried it, however the frames are still too faintly molded. My other option is using painted masking tape which I had used before with good results.

Moving along I painted a strip of masking tape with my homemade zinc chromate to see if it will hold the paint.

And let it dry…

After I will try to mix up some homemade paint using the information I found with the decals I have bought from Aviaeology.

I can tell you right now the painted masking tape didn’t not work.