I am looking for a good condition steel rear valence for my 1.7 restoration. I believe it would have a single hole for the tailpipe to go through, instead of the notch on later vehicles.

Those are hard to find in any condition. Be aware they discontinued that deep design as it reduced hot air from exiting from under the car. It will also only work with a muffler that was made for that valance as the exhaust pipe is in a different location than the 72 and later engines.
I have one that needs lots of work and will sell cheap. Shipping is from California and will cost around $50 to ship.

Sending you a PM. Thanks.

Pic of the exhaust I have on there now replacing the Monza that came with the car when I bought it.