I had an email recently from John Arkell of the SECR Society who has spent some time at the National Archives this year undertaking some research & during which he has found reference to the repairs carried out on No.27 in December of 1922 by the SECR. It gives details of the work carried out, the boiler number 289 and the fact that it was given a new chimney!
The entry is signed by the chargeman Mr J.Sharp on the 23rd of December 1922 with there being no mention of the date the loco entered the works other than the note in the “came in” column 1922, so there is no way of knowing from this document how long the actual repair took.
Anyway, I hope you find it as interesting as I did.
Clive Emsley