I could be wrong, because I'm going on memory here.
I remember reading a SF magazine in the mid-80's when I was in high school, either Starlog or one of the similar ones available at the time, that talked about "The Weapons of Star Wars" or some-such. They discussed the Broomhandle for Han, the Sterlings for the trooper blasters, and I'm pretty sure it mentioned at least the Graflex for Luke's saber. Ever since then, I've been looking for one, and I know it predates (at least my use of) the web as the only way to do it was to scour camera shops, etc.
The Graflex is pretty recognizable even in saber form so I find it easy to believe it would be one of the first "found item props" identified. (Although not as easy as the very obvious Broomhandle Mauser and the Sterlings).
I'd be pretty surprised if it took 20 years for the Graflex (like say from '77 to '97) to be identified as the main component of Luke's saber. All the details? No. Some of them are pretty obscure. But having it known as the main piece, yeah.
I was 10 when Star Wars came out, and I've been reading about it obsessively since then, first through magazines like Starlog, and behind the scenes books, and film making magazines, etc, and then eventually online. I've been around this forum (as a lurker back when registrations were invite only) for quite awhile and remember some of the "big discoveries" like the promo photo that determined the ANH saber had 7 T tracks, etc. I can't honestly remember when I first learned about the Graflex or when I didn't know what Luke's saber was made from.
What do the rest of you think?