Hi,
If those thumbwheel switches are like the ones i've seen,
then they only have tiddley little contacts in them.
I would not think they could drive the lights directly.
There are various contact arrangements available within those
thumb wheel switches, you can get ones with a binary output,
done by the little contacts inside.
I would imagine you could also get them with seven-segment output
lines, but i haven't seen any.
If you can get them with 7-seg outlets, that makes your circuitwork
pretty straight-forward, just a follower on each line.
Best of luck with it, John