Your Eminence, what did the subject of your photo think of it? I'm assuming he saw it. To all others: WD-40 and a bit of muscle fixed the ball head. To be honest, as my hands now have little gripping strength. I used a pair of pliers on the locking key/control/handle -- with a small piece cut from the discarded tube of a bicycle tyre. The FOOMI now works well and is unmarked.
Yes, he liked it. I wander the streets of my small, rural hinterland hamlet, and photograph - usually with my monochrom and go to lens, a 75mm voigtlander, though sometimes with another rangefinder and FP4. Usually a bessa, sometimes one of my favourites, a retina IIc, and I've just had CLA'd a Canon 7 I bought on eprey which I'm going to use over the next few days. The deal with all those who give me permission to photograph them is that I get them a 5x7 print (done at a nearby K-mart - something like Wal-mart - for a pittance, I think about 8 - 12 cents). I am glad FOOMI now works and is unmarked. Bravo and regards.
Glad it worked out for you with no damage. I've read that WD 40 is essentially refined kerosene, and not a lubricant.
A remarkable product - have used many on the first list. Link 34 Brilliant Ways to Use WD-40 at Home The next, a bit too exciting for my taste! Link How To Fix a Tire With a Blast of Fire