I ended up using High Power 3535 Chip 1157 Switchback LED Turn Signal Light Bulbs which I found on ebay:
http://www.ebay.com.au/itm/191482522785From the single bulb you get an amber light and a white light depending on what circuit is activated. I did not need load resisters.
I replaced the original reversing light socket with two Corvette Original Drivers Side LH Taillight Brake Lamp Repair Sockets, connected the yellow wire to the relevant indicator wire and the brown wires to the revering light wire. I had to slightly modify the socket to fit the reversing light lense.
To modify the lenses, I cut the reversing light lense on the seam were the lense and back joined with a jig on a band saw. I painted out the red part of the lense with silver paint and then re-glued the two haves. They look completely stock in daylight.