Originally Posted by
SaturationPt
I don't think that Herman will get back to you unfortunately.
I do know that everything from his house and the large shop area behind the house was sold at an estate sale last fall, he did his speaker work in the shop there but I didn't look into whether Herman is still among us, certainly not in a capacity to recone speakers. I didn't hear about the sale in time or I would have been there opening day and maybe would know more about it. I'm up in Angola, ... not a jump in the car during lunch trip.
I also don't know when recones were discontinued for the 136A from JBL, and whether the cones in your father's L300s are the currently-available ones. At any rate, the current cone kits are made in Mexico, some on this board don't consider that to be good. For me, they're all that is available and I will keep some around for that "what if" in my simple brain. For your father's speakers, I would say that there is little risk to refoaming the existing cones, if they aren't satisfactory then recone next (the cone kits are IIRC around $150/ea. and the closest match foam I've found is Simply Speakers for around $20/ea. or $39/pair).
Refoaming a pair of 15" JBLs is not the best place to practice, the large cone and back-glue makes it tougher than most IME. Maybe edgewound is your best bet on this, and if he's a JBL authorized shop he can also get new cone kits from JBL.
Regarding the L300 / L300A change, I can likely tell you from serial number, or you can look at the woofer magnet to verify 136A. External cues are the crappy plastic twist-lock terminals on the later version, the A is only on some of the foilcals (my very late As do not have the A following the serial number) and the foilcal changed from SUMMIT to MODEL L300 before the change to the 136H, so not as simple as most JBLs to tell version.
Best of luck, let me know if I can help, not sure how local to me you are.