Thinline : Late 70's vs. Early 70s

[variantboy]

My apologies up front for reposting - I first posted this inadvertently to the wrong forum. ((bonking self on head))

Been looking for a thinline from the 70's that has the original Seth Lover WR Humbuckers, and am watching an auction for a '78 right now. I'm just curious if anyone knows if there were any production differences between .. say... a '72 and a '78 - in the guitar itself? in the pickups? I used to own a 72 and *LOVED* the sound of that guitar. Later in life i owned a 78 deluxe, and while i liked it, it was not like the 72 - wondering if that was due to the 4 pot config of the deluxe - or was it the "semi hollowness" of the thinline - or was it something different they were doing with those pickups or the makeup of the guitar. Any thoughts? Would also like a recommendation on what a minty '78 thinline would be worth these days.. i find the blue book all to often to be somewhat unreliable. thanks in advance. -dan