Luke's ESB lightsaber did have a second red button replacing the "glass eye". There should be replicas available if you can't get a real one for a good price.
or if you can't find a second red button, just leave the glass eye and go with a TFA version.
While removing ever tab is one of the reasons why I'd rather do a TFA version over ESB, my main reason is that I want to keep the integrity of the peice.
I don't know why this isn't brought up much, but there were at least 4 or 5 versions of the lightsaber as used in ESB.
-One had two red buttons and no tab. (promo, Hoth, Bespin)
-Another had two red buttons AND a tab (this was a bladed version).
-One had one button, no tab, no eye. (Dagobah - maybe the same as the first minus a button?)
-Yet another had a button/eye/tab. (hand saber)
-And then there was the Vader ROTJ before the end was painted black! (bladed stunt)
That 2 red buttons no tab hero did get more screen time, and was used in many promotional photos, but it's perfectly valid to have one of the others and still call it "ESB"...
Really, the TFA is an amalgam of the various ESB versions... You could convert a graflex with ESB style parts into the TFA configuration and still call it an ESB for now. Then if you ever find a second button, just pop it on and you're in an even better place