Earlier Rogers Ls35a 15ohms sonic differences Vs Later serial# Roger's 15ohms?


Few have said the earlier 15ohm Rogers Ls35a's sounded better than the later higher serial number 15 ohms versions. Is there any documented confirmed proof of this?
The only minor indication is the early serial numbers fetch more money but thats not a proper sonic indication. Could be more of a rarity value.
I do know the woofer of the later versions are a bit different because they say first versions had a flaw. 

Whats your listening experience tell you about earlier and later models?
vinny55
My friend worked as a repair tech at a local hi fi store and examined the crossovers in some Rogers LS3/5A's. He noticed differences between early and later ones. Sonically I heard NO difference! 
@roberjerman good to know. Did you notice the earlier woofers were bit different around the rubber surrounds of the earlier than later serial numbered ones?
I don't remember seeing a difference in the KEF B110 woofers used in the LS3/5A's. They were supposed to be selected and matched per pair. My tech friend said that the earlier versions used an autoformer in the x-overs. As regards sonic differences years ago Hi Fi News did a comparative survey of various versions (Rogers, Chartwell, Goodmans, etc). You might want to check it out - I found it fascinating reading! BTW I own a later production pair made by Rogers.