It's not any of the late '30s (36, 37, 38) as they all had two seperate guages - speedo & 4 in 1 cluster. Cool looking guage, though.
49 50 had 3 gauges speedo and 2 twin gauges all the same size. has to be 29-35 unless it's a plymouth truck some gauge company will probably have one like it on the market next week sometime. another new inovation by Auto-loc