An odd but positive feature of Rolleiflex/Rolleicord shutters, is that with use, the slow shutter speeds often "degum" themselves and auto-adjust to quite close to their original settings. This has happened with several of my Rolleis,notably a black T I bought in the '90s which had acceptable tolerances in the high (above 1/30) shutter speeds but bummer slow speeds.
After a few months of regular use, mostly at 1/60 to 1/250, I did a routine shutter speed test and discovered to my amazement (and amusement) that the slow shutter speeds had somehow "reset" themselves and were working almost normally.
The camera worked well until I finally had it CLA'd in the late '00s, not for any particular reason to do with that Rollei but my Melbourne camera repair man was about to retire and I did a good deal with him to have four or five of my older cameras serviced.
II still use this T fairly regularly and it shoots well. No problems at all. Another T I bought in the early '90s has never had any problems but was also CLA'd with the batch.
Mine seem to be permanently set on 1/125 at f/11 or a tad beyond, for ISO 100 films. For ISO 400 films, move the levers over to 1/500 at f/11. Open up a stop on cloudy days, two stops for deep shade. There you go!
Barring any unplanned accidents I expect my two cameras to go on working well for the rest of my time using them.
Rollei Bayonet I accessories can often be found at affordable prices. The I filters and close up lenses work on all the Tessar Rolleis and the Rolleicord Xenars.
What better could anyone wish for? Maybe if the price of 120 B&W roll film in Australia could drop to A$3 a roll as it was in the 1990s, oh well...