I recently bought a Deardorff and 3 lenses. By the time they arrived I thought to myself "gee, I shouldve bought one of those lens wrench thingies to mount them with". (I live in a country where camera stores think large format means a full frame DSLR sensor)
So I called my favourite camera repair man (Jackie ex-Legend Camera Service) and arranged to drive there - 1 hr each way ... When I got there Jackie unscrewed the rear elements and instead of the wrench whipped out a standard 12" steel rule which fit perfectly into the slots across the retaining ring on all my lenses (Schneider & Rodenstock)! Just so one thing is clear - he had the wrench on his bench, but due to the tapered prongs vs the rules's square edges, the rule is in fact the better tool for this job! I now have one in my case, in case the lens get a little loose one day, but I love learning things like that - thought you might too
You still need a wrench to access recessed rings, like on the front elements and maybe some other lens models, but I won't be messing with any of that and it's a neat trick I think.
BTW - If you live in Sydney and need ANY camera fixed, he has closed his shop and works from home, so call me and I'll give you his number - an absolute precision tradesman and gentleman.