Richard, This is what we would do at work with this material, If you have removed the dial face, Set up a C2 contamination controlled area, (in your case barrier off your garage and area where you worked on the gauge).
You need a Radiological survey of your work area where the gauge face has been within this barriered area, whoever does this will put on a respirator and disposable coverall's and overshoes and rubber gloves, place the dial face in a plastic sealed bag using some long reach pliers. Seal the bag put it in a sealed all glass container and remove to a licenced facility for this waste, (without the glass you are exposed to Alpha and Beta radiation and enhanced gamma).
Any Measurment of counts per second found above background is contamination, they will need to do a proper radiological survey of your work area with an alpha and beta probe, then de-contaminate with approved methods, I dont recommend you do this. What have you actually done to the gauge face?, Have you used an abrasive to remove the paint?
I would suggest contacting Hartlepool Nuclear Power Station near you for guidance on who could carry out this for you. I dont advise you to carry out your own survey.
If you lived closer to me I could have sorted this for you with my employer, it may well start costing you money to bring in specialist to do this de-contamination work for you.
I can dispose of the gauge face for you at my work place. I can dispose of any used PPE, tag rags solvents used above if passed to me in a sealed plastic bag and again I can dispose of this for you.
You really need an independant body to do this work for you, this is the only advice I can give you.
Sorry Kev.
