Henry, This style LED is, in my opinion, the type you want;
http://www.ebay.com/itm/1942-1948-Fo...sories&vxp=mtr
They make them in different styles to suit different cars. I run the 33-36 style they offer in my 35, and I love them! What you do is use the mounted LEDS they supply, but throw away their rubbish plastic lenses, sustituting them instead for your glass ones.
Now...you're gonna tell me you are still running 6 volt aren't you? I could be wrong, but I think that even though these are rated at 12 volt, the current draw is so small [applying brakes in my 35 does not even make ammeter flicker], that they'd work perfectly well on 6 jolts. Brian