So a new idea has just bounced off inside my head, which I shall call 'Custom Parts'. Basically what this is, is a bunch of varying parts made during the initial sprite which can be swapped out to customise it; we're talking about window shapes, lights, extras sticking out of the general sprite, minor details like that. Now obviously this will require more work and thus I won't be able to apply this to most of the sprites that I have made or make in the future, but for the ones that I test this out on should be pretty awesome if all goes well.
I shall use the Bulkhead as an example, with it's default parts applied surrounded by the 'custom parts' in their respective areas of application.
*Window tint colours will also be an option of customisation, red is used by default when I edit sprites due to it's easy HSL values.