Classic Playfields did a run of 350 last year. They literally sold on within a week and had very limited numbers to send to distributors (if any). I'm told there will be another run around the time of the playfields.
Now you need to be careful with a reproduction backglass that you intend on selling. There are license fees applicable to Gottlieb, and any repros need to be checked with Pinball resource and Gottlieb prior to proceeding. There are two license holders in Australia - Flipperresue and Pinballrescue. Shay Group are the licensee for Gottlieb backglasses and Classicplayfields were the licensee for Target Alpha and Joker Poker.
Under the "right to restore" - you can repro the backglass as part of a restoration of your own game.
If I were you, I'd wait for CPR to do their second run.