I am looking at purchasing a c7700 but it has no negative carrier. I need 6x7, I have looked at some on ebay, there are some that say they will fit this (possibly lpl brand?) also I found a Besler 67c carrier. I wonder if this would fit such an enlrger? Or is there any types / brand that would be reccomended which would fit. a slightly unrellated question, is there advantage to having glass or no glass in the holder? Thankyou.