I am intrigued by the ‘under dash’ Ignition cut out switch and Substitute rectifier in you specification. How much were you quoted for the switch and what is the substitute rectifier.
John
This is a "KEY" type battery cut off switch. I usually mounts out of sight and it goes in series to the battery cable, usually the positive, but could be used in either.
In most high performance racing classes, a easily operated cut off switch is required. In drag racing they are usually on the right rear of the car and most of the times there is a rod that you can push quickly to drop power throughout the car.
I had a remote cut off switch on my Willys, but didn't use it much. Because I had power door openers and power trunk/boot, I also had remote battery terminals mounted inside the driver's rear fender that could be reached in the case I had to jump the battery to open a door etc. Also my battery was buried inside the trunk behind a couple panels and not very easy to reach on a good day.
These are the bulkhead type and worked great for my needs.
As far as a substitute rectifier, it may mean that they want to use a Harley rectifier right up front like a lot of guys here have gone to after their short lived M3W rectifier goes south on them. Not sure about that though.