Ok not in the same league as the GR1433 in post #170, and a wee bit older, and the subject of some abuse, but can anyone identify the type of wire used in the Gambrell Bros 4x decade resistance box (photo below) ? The wire can make a joint in solder, and has a form of insulation covering. All coils are wound on the same size wooden bobbin, and are wound bifilar. I'm guessing 1930's but not much info available on Gambrell except for them exhibiting their instrument range in the 1920's and 30's, and they are from England. Nearly every bobbin measures within about 0.1% (only a crude measurement so far with a Keithley 197) so this was likely a base grade lab 1R to 9,999R box for its time.