A4 60027 Merlin's Boiler question

[neildimmer]

Hi all

I have added a photo taken by Tony Gillett at Preston in July 1966 of the boiler from A4 60027 Merlin in the consist of a freight service, does anyone have any idea what this was about, something to do with 60007 Sir Nigel Gresley's overhaul at Crewe in 1966 perhaps?
http://www.steamlocomotives.photos.gb.net/p56772720.html

Also added is a B/W night photo of 60004 William Whitelaw taken at Carlisle Station on the 25th September 1961 at 21:15 pm
http://www.steamlocomotives.photos.gb.net/p56772719.html

Neil

 

[Phoenix]

I'm guessing that the SNG answer is more likely than not cause I imagine they wouldn't go to the trouble of moving a boiler via rail freight unless they had some good purpose to do so.
Were there an A3's still in service at this point as I remeber a few of them got A4 boilers as part of a Refurb and is the reason why Flying Scotsman needs a boiler overhaul as she is on her A4 boiler.