If I use a fish pump control valve would it have to go on the right side of the gauge in relation to the pump and the bagging. So lets say working from the left I have the pump, then the gauge, and then the air control valve?
Or should it be the pump, then the air control valve and then the gauge?

I understand the air valve simply makes the hole bigger or smaller, I did wonder if the air valve was meant to purposely leak air into the pipe to reduce the pressure to the bagging but the one I'm getting doesn't do that, as I said it just makes the hole inside the pipe bigger or smaller by screwing the tap in or out.

You'll need one that allows some air into the flow to reduce the vacuum - make the pump work a little and reduce the vacuum level facing the bag.  This is really only a good idea if your pump is an oil-less one because over time oiled-lubricated pumps will exhaust oil mist and make a mess - if you have one plumb the exhaust out of your work area.  The gauge should ideally be on the bag side of the regulator valve so you can see on the gauge what your vacuum is going to the bag.  It would work on the other side too, but not as accurately.  

You could use a T-fitting and place your fish tank valve open to the air and just close it almost completely - so that it lets a small amount of air through.  If it can regulate small volumes then it should work.

Here's a sketchy sketch:

Thanks for the reply. Yeh my pump is one that has oil so exhausting it away from the work area makes sense. I thought it would be better to allow air into the flow so thanks for the conformation.
I must say as well top marks for the sketch Chris, not sure I could have done better myself lol

A good regulator should not cause pump issues as the line between the pump and regulator will be almost at full vacuum and thus the pump should be under negligible load and as such should not  be throwing out any oil mist. 

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Warren, do you know of any regulators like this that are modestly priced?  Only ones I have seen are $300US or so... I'd be interested in one if I could find one but mine are all the cheap bleed-air ones which I don't dare use with a high-vac pump because of oil-filter issues.  Love to have one but for $300 I can buy another low-vac pump...  Thanks!