Hey, had a customer bring in a badly trashed pair of L56s (successor to the L40)...
In his, he had one blown 034 tweeter, and NEITHER of his woofers were original... and weren't even the same as each other...
The cabinets weren't that great... and not being willing to sink serious money in restoring them, the guy asked me if I could just load them up with something that would make them work OK.
Well, the woofer wasn't hard... someone I know had already tried substituting the Parts Express Dayton 10" (#295-315 from PE) for the 127H in his L26s (he had them in there while his 127s were being rebuilt), and they worked quite well. So, in with a pair of 295-315s.
This left the tweeter. I knew the guy didn't wanna spring for the $$ for an original 034 or rebuild kit, so I went scrounging around my parts bin... and found, of all things, a pair of EPI tweeters from a pair of EPI 100V speakers from the late '70s. Wouldn't you know it, but not only are the EPI tweeters EXACTLY the same diameter as the 034, but the BOLT HOLES EVEN LINED UP. In they went!
And you know what? It sounds SO much like an original L40, that if I didn't know already, I'd have to remove the grille to tell it wasn't original. The tweeter is a perfect match in sensitivity, and the woofer parameters are close enough, that the original cabinet tuning still works... the standard "JBL bump" is there, right where it was originally!
So, if you really wanna make a cheap L40/L56 clone, find yourself a pair of the EPI tweeters (I found the pair I robbed these from, at a thrift store for $8 for the pair of cabinets, with rebuildable woofers and working tweeters!)... any of the black-with-gold-ring EPI inverted domes should work- and get a pair of the PE Dayton woofers (about $23 each plus shipping from PE believe it or not!), and make a duplicate of the L56 crossover... all I gotta say, is that it works!
junkyard speaker king!