Gunner history books find the three month uplifting of the 23rd Regiment to the exalted status of Horse Artillery somewhat of an amusing chapter in Canadian artillery circles.
The intention was that SP regiments, being "mounted" would all be RCHA. As soon as the order was received in the 23rd Regiment, the officers had their battle dress modified to include "ball" buttons (ball buttons are shaped like small balls as opposed to flat or semi rounded buttons and were a dress item exclusive to the regular army RCHA officers within the artillery. On battle dress these were represented by leather wrapped ball buttons on the type of battle dress jacket without hidden buttons (obviously). The other ranks replaced their cloth accoutrements with brass (the cannon above a Sgts' rank stripes for example) as this was also an RCHA priviledge.
Regular Gunners scattered throughout the army and the officers of 1st Field Regiment, RCHA were most upset and were worried that the 1st (and finest) regiment might lose its RCHA status as it was towed and therefore not "mounted". As you can see it took three months to "fix" the problem and the members of the 23rd and other SP regiments were devastated to find themselves back in the mundane ranks of the Field artillery and were directed in rather short terms to divest themselves of RCHA priviledges.
Of course, Gunner history shows that as the regular artillery grew post war (eventually to five regiments and currently at three) each was granted the style and priviledges of the Royal Canadian HORSE Artillery, SP or not! SP regiments in the militia (we quite a few in the 50's) were always RCA never RCHA.
From the point of view of a third generation Gunner who wore RCHA for many years, its all rather petty, really.
Cheers and Ubique!
Mike