If you're gonna do this, I would scan the original dials. Put them on the scanner bed with a piece of white paper behind them.
You'll get a much better image from them and if you do it right, you can also maintain the correct size.
Getting them to print out in the correct size will be the biggest problem, that's why it's got print and resize until you get it right, no reason why it shouldn't work though.
But using Word to create your new dials?

Do it in a decent graphics package, then you can layer it much better.
(Graphical designer rant off)
!m!