Near to me is a repairer of gauges and dials who can make new copies of the faceplates. He would need one to copy. The cost would I believe somewhere around £50 for the mask + the cost of the new faceplates. If you are interested let me know and I will speak with him to get more details.
I only make a adhesive backed vinyl "decal", not a replacement face. The ammeter is the worst instrument to replace the face on, as you have to lift the dial over the ammeter needle. This is impossible to do without bending the needle. Sometimes that results in a broken needle.