Oh to keep tach dash or NOT?

[Desert Rat]

Have a 79 Blazer 2wd with a 402,just put all white face overlay gauges in it,now i found a tach dash from a 79 and bought it,gauges looks so cool,i hate to put tach in,maybe id better just get a white faced Autometer and sell this one?Ive had them from 73's before are they worth the same or more/less.I had a hard time finding one with Volt gauge.but got lucky Sat at boneyard.Or is it a better ebay item?it does work.lens is a little faded but im sure would polish up,AZ sun is hard on that stuff.