Looking around at other people's cars, it seems to me that the biggest place they goof is with the steering wheel. If you have a mostly stock looking 1973 interior, you need a wheel that matches it. If you have a very modern interior, you need a modern looking wheel.
I would think something along the lines of a Momo Prototipo would match your interior very well.
A nice Nardi can be had second hand for about $100, like this one.
or this one.
All of these pics are right off of Ebay, so a quick search should turn up something that will match your car well.
Shiny Side Up!
Bill