Robed

depends which crest you are using, the earlier Lion on Wheel the lion being just a totem made up by BR faces forwards on both sides, the later Ferret and Dartboard being a proper heraldic crest should not be reversed so the lion should always face to the left irrespective of which side the emblem is on. There are exceptions as the heraldic rules were not made clear in the first few months of application, so a few locos in 1956/7 had the later crest reversed on the right hand side so that the lion faced forwards. Clear as mud?

Thanks for this Iam making 71000 loco with BR1J tender so would be about 1957 ish so will apply the relevant rules

thanks for the reply

The 'unicycling lion' totem was appled to locos coming out of works through paint shops between 1949 and 1956, when the the 'ferret & dartboard totem was used.  As Redgate has said, the ferret & darboard was a proper heraldic device, and as such had to be approved by the College of Arms and obey the rules of heraldry, which are set by the College of Arms, an officially authorised body.  The rules are complex and cloaked in medieval High French, and one of them is that heraldic animals, including of course the lion on the ferret and dartboard, must face to the left of the device as viewed from the front. 

The unicycling lions, not a heraldic device but simply a logo, faced towards the front of the loco it was used on, be it tender or tank, and where there was doubt about which the front was, such as the LMS and LNER Beyer Garratts and the various diesels, electrics, and gas turbine, it faced towards the smokebox or whichever cab was nearest.  On multiple units it faced the nearest cab.

When the ferret & dartboard came into use, this practice continued, with the lion looking as far as possible as if it was facing the way it was going.  This contravened the College of Arms regulations, and once that august body became aware of the situation, it issued an order to the BRB to rectify the situation forthwith, or else.  As nobody wanted to be put in the Tower for painting a loco, the Board complied, replacing such lions as were facing to the right even if they were henceforward condemned to a life of going backwards. 

Duke of Gloucester was a high profile engine, and one would expect it to carry the latest livery most of the time.  To ascertain which totem(s) it's tender carried during 1957, right in the transition period, will need to be researched and as always the best information is dated photographs of good provenance.  Luckily the engine's uniqueness guaranteed a lot of attention from photographers.  According to Wikipedia, the BR1J tender was not provided until 1958, so the loco's original BR1E was still coupled to it in 1957.  The BRIJ tender would certainly have had it's lions correctly left-facing and conforming to the College of Arms' rules.

I cannot help wondering if all this directionist faffing about had any part to play in the double-arrow corporate identity logo, which sort of faces both ways at once.  We called it the 'arrows of indecision'.

Sorry no idea!.. ask again in "Help - Hints and tips" section for a better chance of getting an answer.