A trick to help shooting chrome or very reflective surfaces is to use white card or paper as reflectors. And avoid hard light sources. You have to shoot at an angle or else you'll see yourself reflected in the thing you're photographing. One way around that is to either use a light tent or shoot from a crack between reflectors. I use a softbox as a light source but obviously not everyone will have access to one so using thin paper or a white sheet as a diffuser can help.
Usually for something like an effect pedal a pair of white cards around A4 size should help enormously.
Cool build BTW!