I buffed out a pair of 2352's way back when and made a thin steel bracket across the face and put a 2404 tweeter centered on it. Behind the tweet magnet I added a foam cone ( tapered ) to diminish the mid reflections and *think* the crossover was about 5K but sadly the notes and pics went with the customer...
Each bass cabinet was a quad 15 ( 8" cardboard tube vents! ) with 2225H's powered by a crown delta2000...biamped with a 5235 at 800HZ and a crown PS400 for the HF.
MAN that was fun to listen to...
Nice job on the fiberglas - next time I play with those horns I will take them to a corvette body shop....