This company will rebuild your stock speedometer and gauges, but add modern electronic internals. I talked with them some time ago but have never sent mine to them. Again, not the cheapest alternative, but a neat solution I think.

http://www.redlinegaugeworks.com/default.asp

They used to have a set of 47-53 gauges in their gallery, but have reworked their website since I was looking and must have took them down.
Scott

1947, 1950, & 1952 Chevrolet 1/2 ton
1952 GMC 450 series Cab Over Engine
1946 Chevrolet 2 Ton