Miss Prism

Is that a 10' wheelbase?

It's a total disgrace we didn't get the Churchward Line.

It is possible I suppose that the tank on 1361 is the same one, six months later, on 1365.

Here's 1365 (at Swindon, 1 April 1949, after a smokebox and chassis renovation and repaint) also with just 'G W'. I've no idea why. ('G W R' with the W on one side of the middle rivet ring fitted ok, as on 1364.) Impossible to tell whether your 1361 is green or black.

The weird thing about 3335 is that it seems to have changed frames, bogie, and rods at some stage.

3335 with a rare vacuum-cylindered early Dean 3000g with 'G W R' insignia. Date unknown. Could be wartime black.

https://www.warwickshirerailways.com/gwr/gwrt1452.htm Again, this is 1908, but I think the dark colour used for the lower part of the walls continued even after the arrival of dark stone. The colour of the smoke hoods is unknown. They didn't last like that for long!

The pictures you show are pre-WWI, when chocolate was commonly used for the lower part of shed doors. That colour probably continued to be shown until a repaint, which would likely have been in light and dark stone. Here's Marlborough in 1929: http://www.gwr.org.uk/water-cranes/1499-marlborough-23may1929.jpg

It was perfectly normal for a loco and its tender to have different buffer styles.

Pannier tanks on the Southern Region

We called them 'Coffee pots'.

1924?

6378, at OOC, September 1933, with a flush-riveted front smokebox ring and snapheads on the rear ring.

12" head diameter for the early period transitioned to 13". Not sure when the changeup started - was it with the general adoption of other RCH things?

Smokebox riveting, like many other GWR things, was an evolving situation. Flush-riveted smokeboxes featured on all early builds, up to c 1922 *. After that, rivets began to appear on the rear smokebox ring, and then full (front and back ring) riveting became establish from c 1928. These updating patterns were established on new build and on works visits of existing locos. Rarely, snapheads were on the front smokebox ring and not the rear. Also, some/many older smokebox wrappers continued in existence. And of course, boiler swapping meant that locos could have different appearances from time to time. Not sure when the last flush-riveted ring could be spotted - 1937?? Edit: * Probably more like 1919/20, from evidence of lot 209, although subsequent lots 210 and 211 were probably built flush-riveted.

My view on the state of Moguls in BR days is that the lined ones were kept fairly clean (at least an attempt was made to keep them clean), but the unlined ones were left to get extremely grubby. Even the lined ones could look uncared for - here's a lined 6313 on station pilot duties at Reading on 28 March 1959. It lasted only a couple of more years, so I doubt it ever looked respectable again. Reading shed's cleaning resources were getting very low by that time.

Here is a tender attached to 7802 at Swindon on 12 November 1961. There is no lining on the fender. Collett parallel buffers. Late size (large) spring shackles. Cab sheet ready for the Welsh rain.

Collett Goods had steam pipes at the front.

I assume there was only one edition?

Yes, but I think it emphasises the point that SRMs tied up specialised resources at the works. Uncoupling an 0-4-2T from a trailer car was far easier...

Boilers could be lifted out through the roof hatch. Swapping the drive bogie entailed lifting the front of the body about 15' into the air.

5322's cab has the steam heating valve and pipe. Just seems a bit odd the fronts of the Moguls weren't steam-piped.

Why didn't the Moguls have steam heating pipes? (Or am I missing something obvious?)

Dave Franks = Lanarkshire Models

Doesn't sound too difficult to fashion a round washer (as the new 'lip') and fit replacement heads. (Although drilling out those self-contained stocks is always very delicate because of the diameter of the shank.) Or file off the existing head and fit a replacement? Or fit some new Dave Franks ones? Shapeways does new stocks for the self-contained variety. It's not a deal-breaker for me.