I know this might sound counter-intuitive, but for small scale maps (regional / continental) you really don't need spacio-mechanical skills to any great degree. It's more a question of following procedures and tinkering with them to find a result which pleases you.

In terms of city design, yes, I think you do need to have some idea of 'dimensional fit', but you don't have to be Da Vinci.

I'm very suspicious of tests which seek to asses how able a person is to do a thing apart from his ability to take the test in question.

Anyway, if you'd like someone to take on your map requests, then I suggest you post it in the map request forum. I'd give it a go myself, but I'm strapped for time at the moment. Bear in mind that city maps are very time consuming to draw, and more detail in your description would be helpful to anyone looking at taking on your commission.

Good luck with your map request!

ravells.