I hope others find this useful.
My trailer uses 1/2" Qest fittings and polybutylene piping for water distribution. In my area, these fittings are as rare as hen's teeth, particularly the insert steel gripper. To get some parts, I must have hit a dozen area RV dealers. I want to stay with this piping since it is most forgiving when a little water is left in the lines over winter.
When I stopped at my local dealer here in Spruce Grove to pick up an order, and metioned my problem with these fittings, she directed me to the local RONA. It turns out they carry Push'N'Turn
fittings that are intended for RVs and are an exact replacement for Qest fittings. I finished my plumbing upgrade and it wnet splendidly.
Here's a photo of one of the packs.