Good Morning, Judith,
Where is "over here"--Hawaii?? Anyway, I am not familiar with the 67C, but I would imagine that heat absorbing glass is available. The enlarger has a filter drawer, doesn't it? If so, that's where the glass would normally go. It shouldn't be an expensive item, unless you have to order directly from Beseler. I'm not sure about other suppliers, whether it's something an ordinary glazier would have in stock or not. Incidentally, you probably will have a several-lifetime supply of Negatrans O-rings if the five you've ordered work out OK. My Negatrans is over twenty-five years old and only recently did it begin to show signs of slippage.
Konical