If you can get the PN off the back of your gauge, just give VDO a call for the correct sender PN.
VDO - USA
http://www.vdo.net.au/media/189570/2...-catalogue.pdf
Using a snake camera (borescope) you can usually get easy access.
https://www.amazon.com/gp/product/B0...d_i=4989317011
But VDO PN 360-006 looks like what you need. Still a guess not knowing your gauge PN. (Doesn't have the redundant warning switch which your not wired for anyways)
https://www.amazon.com/VDO-360004-15...ywords=vdo+360