Hey Owl- you're certainly up for challenges....kudos to you. You mention panel line shading, and I'd like to share something I read recently. A guy who used to hang out here, DoogsATX (Matt) has a blog. It's got some useful ideas, I think, and he's come up with this alternative to panel line shading that he calles black basing. It's a result of this issue which seems to be somewhat misunderstood in the modelling community.
Just for clarity, I'm not trying to 'stir the pot' here; rather, I'm simply hoping to share a technique and an alternate point of view in hopes of adding to the 'modeler's toolbox.' Panel line shading can produce some very nice effects, but maybe 'black basing' can serve as alternative approach to a realistic finish and possibly lead to other variations on weathering/wear and tear?
Dave