Gauge dash build

Hi just started the build of my gauge Center for egt, coolant , volt and turbo boost gauges before I fit new timing pump boost pin and tweak fuelling.

I seen this done by rover Tasmania so wanted to have a go .
Ordered a bucket to suit the size needed for the dash
Cut the base the same shape as the dash.
Market out my egt , coolant , turbo boost and volt meter hole sizes just waiting on a digital clock and a double USB port with a 12v cig adapter socket in post
Clock and usb/cig going underneath the 2 with out any under .
Cut a panel on top for access.
Followed by a lid just need to work out how to decorate it and fix it all down . Then the wiring going to be the hardest part for me As I do not know how to run a live from fuse box and don’t want to run direct off battery In case it don’t switch off .

any help for running a feed to accessory fuse box that works on ignition .
Any help appreciated barring in mind it’s a p38

Pictures never worked

Few pics of the dash mount gauges now fitted just needs fixed down and secured , and a can’t get the coolant temp gauge to start from 0 it starts from 1200 and comes down . Same with turbo gauge it’s starting with 9.5 instead of 0 , must be me wiring but al get there