|The grime inside isn't doing any harm - it has taken 74 years to build up. I reckon that's part of its heritage and I'm positive I'd do more damage removing it than leaving it alone|
I have figured out the solution to the sticky tab illustrated in my previous post.
Removing the left-hand rear dust cover reveals the motor and what I'd originally thought was a retaining collar for the clockwork motor's spindle. At second glance (and in better light) I spotted a worm gear. A drop of oil and a trial and error turn in both directions and voila! No more sticky tabs and enough pulling power wound into the spring for the carriage to move briskly along to the set tab. If I hadn't had all the covers off again for a more thorough cleaning of the paintwork, I'd probably never have spotted that worm gear.
I hope this is of help to any other Royalists (aristocrats? typocrats?) with sluggish carriages. This fix took two full rotations of the motor spindle to load the spring sufficiently. To save straining yourself with heavy carriage returns or stressing any parts, slightly over-wind the spring first and then gradually slacken it off until there's just enough tension.