I used to build these for Mr Levy. The P-10 is a 3 1/2 way, incorporating a 15 inch "passive damper" that crossed over mechanically at about 60Hz and was 3db down at 16Hz or so. The woofer was made by Becker. Any 15" (preferably paper) passive can be used to replace the original, but it must have an added 16oz weight hot glued to the center and be suspended from an internal support in the middle of it's linear excursion with 1/4 inch rubber bands, such that it returns to center when flexed. It was attached with t-nuts, so it's easy to remove and install. If you have the original damper you might use the original weight. We used heavy washers and eye bolts. The tweeter is a Panasonic leaf, quite good for it's time. Replacing it will probably require adjustment to the crossover. The speaker sounded best at the time placed 1/3 into the (preferably large) room and driven by high power push-pull amps like the CJ Premier 1 and Quicksilver M190, or really good sand like the Bedini 25/25. Its strengths were great imaging and bass equivalent having two subs. Tonality could be adjusted slightly by toeing them in, but your best bet was to be VERY accurate in placing them, relative to the listening position. In an equilateral triangle with the speakers the base and the listening position the apex, they would disappear.
The cabinets use high quality wood veneers and black Formica tops. Finishes included walnut, light oak, and Brazilian Rosewood, and we made a few with 10 coats of black lacquer painted by a car painter. We had a lot of fun back then, but they were very expensive to make, since Mike used high quality parts, including the best caps and resistors, and parallel leads composed of Kimber Kable and Live Wire, equating to 10ga internal cabling, which required one BIG soldering gun!
That's all folks!
Best Wishes