Hi, I am new to this forum. I've recently acquired a Rollei 35 Tessar in mint condition. Lens barrel moves very nice. I worry however, that if I use it extensively I might as well provide some lubrication on the shiny barrel to prolong the nice smooth motion. Of course I do not know if this is common practice for this camera. There is some sort of slight grease on the barrel already. Any ideas suggestions? What kind of grease would it be? I could not find anything about lubrication in the repair manual, except for some oil part numbers... Thanks.