If you are located on the continental U.S.,you might be able to find a gage repair house that has some used parts or knows where to get used parts for older devices. I often use a gage repair shop in Maine called Mainely Gage that I have had some luck with getting older devices repaired. The owners name is Tom Hill, the phone number is (207) 698-5107. He is retired and works part time and doesn't always answer the phone, but I find that he can often find and repair things that others might not want to bother with if you have a little time and patience and he is very reasonable.