Aloha Julian,
I found this artical that describes how to fabricate replacements. I may have found on the BCF, but here it is:
Title : Gauge Repair
Author : Scott Suhring
Here is a tech tip that I recently wrote for our club newsletter (when you're the editor, you tend to write a lot of articles) on this exact subject:
Anyone who has disassembled their dash gauges can appreciate the frustration of first trying to remove the chrome ring that holds the glass secure to the gauge and then finding the dried up remains of the rubber gasket (if that is what this material ever was). Well, certainly one of the parts distributors must have these, but when you look in their catalog or check the parts manual, low and behold they are not listed. The reason for this is that the gaskets came as part of the gauge, which was produced by Smiths/Jaeger. So what do you do?
I have tried various materials and have talked to others that have used everything from windshield glazing to using the gaskets that are available to seal the gauge to the dash, none of which provide the proper seal for the chrome rings. The solution I have devised is to make my own gaskets. To do this, you will need the following materials:
1. Permatex "The Right Stuff" gasket maker (part #29208)
2. Universal Pump Dispenser (this is a plastic syringe found in the glue section of your local hardware store)
3. An Exacto knife or any arts and crafts sharp cutting blade
4. Q-Tips
5. Pam cooking spray
6. Small screwdriver or dental pick
The Permatex gasket maker is a silicon-based material that cures to a flexible rubbery composition that is easy to work with and makes a great gasket. Here is what you do to make your gasket:
1. Clean out the inside of the gauge cover ring of any of the remains of the old gasket.
2. Cut off the tip of the syringe to the size opening that allows enough material to by pushed out to the thickness of the gasket you need to make.
3. Depending on the number of gasket you will be making, fill the syringe with the Permatex.
4. Spray the tip of the Q-tip with the Pam and wipe this on the inside of the ring, but do not saturate the surface.
5. Take the syringe and evenly apply the Permatex in the grove for the gasket to the height just below the inner lip of the ring. You will get some "waves" in the material and uneven application, but this is okay. Just be sure that it is a continuous bead of material that fills in the grove.
6. Let the Permatex cure for 24 hours.
7. Using the small screwdriver or the dental pick, work this under the gasket and pry up the gasket until it is released from the ring. There will be some spots that the Permatex will remain stuck in small bits and these can be removed by just scraping them off to clean up the surface.
8. Using the exacto blade, trim the gasket of any uneven areas or bulges. Don't be shy since the material is very pliable and cuts easily.
You will not have a perfect looking gasket, but this will absolutely provide you with a good seal and one that will remain flexible for the next time you need to disassemble the gauge.
Hey Guest!
Hey - did you know if you click on the title of a thread it will take you to the first unread post since you last visited that thread?
but were afraid to ask: 
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smilie in place of the real @
Pretty Please - add it to our Events forum(s) and add to the calendar! >> 
