One word on this post: CAST STEEL
The elevator cap I've been reposting on lately was cast and forged in steel. As some of you know, cast steel has a peculiar surface roughness that poses a particular challenge to modelers. Steel is usually cast in a negative sand mold made from a wooden or steel master form (positive = looking like the desires end result's shape). The sand let's go in certain areas, particularly in corners and therefore, a smooth sheet of plastic can never stand-in for the real cast surface.
You can get an idea about the roughness of the surface of the elevator cap in this picture
Unless in areas that were machined post casting, the roughness remains apparent.
To model this, I used a technique used by many armor modelers like me, notably for WWII Russian tank turrets that were often cast. I thinned putty (can use Tamiya putty, but I usually use car body putty) with Tamiya extra thin cement. You get a liquid mass that can be dapped onto the surface using an old brush. Mind you to use an old brush, since cleaning them after the application process is finished will require a lot of thinner and in fact doesn't pay.
I applied the putty-cement brew onto the surface, here is the result!
Happy modeling!
Michel.