Does anyone know what issue of MR had the article on removing dynamic brakes or any articles on that subject?
I don’t recall an article on that specific subject, but many locomotive kitbashing or detailing articles include that procedure. What locomotive are you dealing with? Sometimes it’s as simple as removing the section of the top of the hood that has the dynamic brake fan and resistor grids and replacing it with the section that doesn’t.
Back in the late '70s or early '80s RMC did a series on Paducah rebuilds including an HO Scale construction article; the Geeps used had removable dynamic brake housings. Some time later someone did an N Scale conversion article; N Scale Geeps did/do not have removable dynamic brake housings and they had to be either cut out and styrene used to fill the gap or they had to be filed down. There may have been an HO Scale article covering removal procedures but this N Scale article is the only one which comes immediately to mind!
I don’t know how much replacement body shells cost these days but I would say get yourself a file and lay into it - carefully, of course!! I’m going to do such with some N Scale GP35s.