[Dan in MI]

Attached is a picture of the diffusers I removed from my 49 IP. I disassembled the cluster to get at them. To remove you need to straighten the 2 tabs on the chrome ring that holds it in place. The tabs are on the backside next to the light socket, see attached picture. after the ring is off the diffuser will probably be stuck due to the cork gasket. I used a piece of wooden dowel from the backside and tapped them until they came off.

I am still using 6 volts and replaced the bulbs with LED ones. It is bright now. One thing to consider is the glare on the windshield from the bulbs at night. This is a common complaint, maybe using the dimmest bulb that still illuminates the gauges would be best.