There are Mk1, Mk2, Mk3, MK4 and MK5/DC Versions of the Loxton 5
Mk1 Pre August 2012 Has a single top brick (baffle) which sits into the cut ou in the rear brick.
Mk2 August 2012 - march 2014 has two top brick Baffles (One upper and one lower)The rear bricks are straight.
Mk3 March 2014 - October 2018 has a single air control, two small top brick baffles supported by a bracket.
Mk4 Nov 2018 - onwards. Has a single air control with a hammerhead lever.
MK5 / Dual Control - Cast Iron Door and two main air controls below the door for primary and secondary air, as well as a third air lever for tertiary air.