Which side the white hackle??

Greetings all - I'm a new member joining your forum to do some research on RWF full dress uniforms.
I recently fell upon a couple of photos from 1968 of the 1st btn RWF on parade in Cardiff. One shows the corps of drums, the other the sappers. What immediately struck me was that the white hackle was on the LEFT side of the raccoon caps, rather then what I knew was "usual" - being on the right side.
On your forum photos I found a few more examples of the hackle on the left with drummers and sappers in full dress, all dating from 1967-69. Photos before and after this short period show the hackle being worn on the right. My reference books on military uniforms and dress regulations all state that the hackle is on the right side.
Can anyone enlighten me as to what was going on in mid to late 1960's with the full dress cap and dress regulations? Any info would be greatly appreciated! I attach the photos in question.
Many thanks!
Ivars Taurins
https://rwf-forum.co.uk/vBulletin/at...tid=7978&stc=1https://rwf-forum.co.uk/vBulletin/at...tid=7979&stc=1https://rwf-forum.co.uk/vBulletin/at...tid=7980&stc=1https://rwf-forum.co.uk/vBulletin/at...tid=7981&stc=1https://rwf-forum.co.uk/vBulletin/at...tid=7982&stc=1