No worries - so you're adding a console?
From what I've read - hopefully others will chime in here - the best/most accurate way for the Voltmeter is to go straight to the battery with the sender line. The wire doesn't need to be very big.
Have you decided on an approach for running wiring to the engine compartment - or is that part of your question? Here's a link to some input on that:
http://www.914world.com/bbs2/index.php?showtopic=316570Do you have a "taco plate" for your temp sender?
There is OEM/Stock or there is this:
https://914werke.com/shop/ols/products/taco-plate-assemblyOil Pressure - I'd suggest reading this and using your stock oil pressure sender for the idiot light and then adding a single pole (or the one you have and just use the gauge side) for the gauge.
https://vwparts.aircooled.net/VDO-80psi-Oil...m-p/v360006.htmand there's this:
https://www.pegasusautoracing.com/document....DocID=TECH00129You will need to run the oil pressure sender off of a remote hose - senders other than the stock one that controls the dash idiot light won't fit through the tin.
I haven't done this yet, but i've been planning it and collecting parts - to me, an ideal setup is the 42 Draft Designs kit is great - but NLA. I found one that a lister here had and it's waiting to go in. Perhaps you can find one:
https://store.ngpracing.com/42-draft-design...cation-kit.htmlHopefully this gets you started and some others will chime in (and correct me!)