First of all I am pretty new to this area. I had an old 35mm but just got my first digital SLR. I had the good fortune to come across a guy selling old lenses from an inheritance. I have purchased three that seem to be in good shape. I was trying out a canon 135 2.8 with soft focus for possible purchase. In the process I swapped the rear lense cover around on several lenses. Now I have found mold inside the last lense with a spot on the rear cap. I fear I have contimanted my other clear lenses by placing this cap on them. Any advice on what to do now. I have all the caps off now. Thanks in advance.