I was recently gifted with a "box-o-cameras" that included a small Rollei hood in a leather pouch. I understand they come in a number of different sizes, and am wondering how to identify which this is. The top says Rollei, F&H, other size has a R script, then a 1, and "Germany" under it. I imagine these may not help too much. The inner diameter of the ring is just under 1 1/2"