hmm.
The original L6s pickups were VERY strong, very bright. They used Lawrences "Super Humbucking" three magnet configuration, which allowed fewer turns, which brightened the output, and still retained the "power". They were ceramic magnets, fully potted in resin.
I'd go, personally, with an underwound set of Fralins, or the Burstbucker #1 in both positions. It wont be "the same" but will be a very nice toned guitar. (the original being sorta bright, with its all maple neck and body)