This kit is for the right-hand drive unstreamlined Gresley Pacifics. You can build the engines in their original condition as class A1 or after their conversion to class A3, until circa 1952-54, when they were eventually converted to left hand drive.

Variations/modifications incorporated into the kit

Cabs: The first eleven engines were built to the generous GNR loading gauge with high cabs. The remaining engines, except for 1481N, were built to the reduced, composite LNER loading gauge with lower cabs. The first eleven had their cabs altered to conform between 1928 and 1933.

Cab sides: on the lower cabs the original cut-out was increased in height by 11" at the same time as bucket seats fitted.

Chimney: original high type for GNR loading gauge and lower type for the LNER composite loading gauge.

Dome: original high type for GNR loading gauge and lower type for the LNER composite loading gauge plus the two types of banjo domes fitted to the A3 class with the later boiler from 1940 onwards.

Firebox: All the fireboxes fitted to A1 class boilers and to the first five A3 class conversions were similar in appearance with four washout plugs on the left hand side, and three on the right. With the next batch of boilers, the numbers of washout plugs were increased by one each side.

Firebox crown washout plugs/door covers: Originally square ended plugs and from circa 1936 onwards circular covers.

Safety valves: original large type for GNR loading gauge and smaller type for the LNER composite loading gauge.

Frames: Differing frame lightening hole arrangements. In their original condition these engines had four large oval holes together with a 12" circular hole ahead of the cylinders. However due to the surprising frequency with which frames were replaced or repaired the large holes either disappeared, were plated in from inside or were replaced by the 12" circular holes that were standard on the later new A3s.

Frame rivets: The original engines were built using countersunk rivets and so give a smooth appearance to the frames. Many photographs show a gradual change to rivets with a visible head as frames were repaired or replaced.

Valve gear: All the engines were originally built with short travel valve gear with narrow platforms and steampipes which extended down to the level of the footplate. Between March 1927 and May 1931 they were rebuilt with long travel valve gear with wider platforms and shorter steampipes. This change alters the length of the crosshead arm and the arm below the radius link.

Bogie:  Originally the engines were built with the swing link bogies which were converted to the helical spring type circa 1933-34.

Bufferbeam: The first twelve engines had a rectangular bufferbeam. The corners were subsequently cut away to clear at the platforms at Newcastle later engines being built with this modification.

Front footsteps: Nos. 1472-81 were originally equipped with a light bar iron type. These were all removed by 1927.

From 1935 onwards all the engines were fitted with a plate type and at the same time small grab handles were fitted to the front drop plate.

Rear Steps: Nos. 1470-80 were built with a width of 8' 8" over the steps. The remainder were built with narrower steps with an overall width of 8' 4".

Front end cover plates: Small cover fitted from 1933 onwards.

Rear spring retaining brackets: Fitted later.

Anti-vacuum valve plate - Two types provided.

Cab seats: original type replaced with bucket seats from circa 1935 onwards.

Lamp irons - footplate: second lamp iron on right-hand side removed from 1931.

Lamp iron - smoke box door: two different types.

Reversing rod: Different shape depending on whether Doncaster or North British built.