I have a sandblaster guy that I use regularly, mostly for paint only.
When I gave him a frame with powdercoat on it to sandblast, he said it would not be worth it as it would be too rough.
From the look of the frame, the rust has got under the powdercoat and lifted it up, so it may not be a major issue to get it off with a chisel-like tool.
Guess I may have to get into it myself before getting sending it to the sandblaster. Care to have a go at painting it with two-pack when I've finished stripping it Mr Magoo?
Mark