A couple of years ago I bought a "Dave Hills" center stand for my newly acquired Vincent Rapide. (Now unfortunately it is Dave Hills RIP).
The change involved changing the rear engine plates---- the new ones were supplied as part of the kit.
The engine plates and stand were supplied unpainted.
I degreased the components applied a phosphoric acid solution and everything looked good.
I then applied a coat of POR-15.
The stand looked fine but the engine plates went all wrinkled.
I removed the paint from the plates, degreased and repainted.
Same wrinkled result.
I decided that the problem was that the plate had been contaminated by oil used in the rolling process which had been rolled deep into the surface of the plate.
Part of the reason I came to that conclusion was that the flat faces of the plate were wrinkled whereas the paint finish on the edges of the plates was fine.
So I removed the paint from the plates (again) and then sanded them down with coarse then fine emery paper.
Repeated the painting process and the paint finish was fine.
HTH