Dear Mr. Mengot (and Daniel)! Countless thanks for such a detailed, comprehensive answer - and for 'Roy Mengot's Titanic Page', as well!
This is exactly what I need, superb!
Funny story was told by Hugh McRoberts, the joiner, as you know: they damaged one element of the Grand staircase's newel during these decorating works, and they decided to disguise it with the mixture of glue & sawdust. So after the final polishing the split wasn't visible :>
Anyway, I'm deeply thankful for sharing this principal info!