I think the availability of newer kit for some Reserve units may have been influenced on how close the Reserve unit was to a Regular Force unit. In the case of my old Reserve regiment the Lanark and Renfrew Scottish out of Pembroke, when I joined in 1978 we had second-hand combats and boots but new berets. We were though issued with 1964 Pattern Web along with C2 Rucksacks which I think was due to our proximity to CFB Petawawa. At the same time the Reserve regiments in Ottawa were still being issued with 1951 Pattern Web (along with some 1937 Pattern) and either made due with the Large Pack or the C1 Cargo Pack. If I remember correctly, we only got issued respirators for Gas Hut training. The L&R finally got Balmorals in about 1980 and I remember a tri-wall of used ones showed up, some from WWII which the SNCOs scooped up, but most were from the 1960s and had been used by the Black Watch.
We got issued winter kit in the fall of 1978 and it was for the most part all new and of the current type in use. The only really old piece of winter kit we were issued was the white Rucksack cover which dated from the 1950s.
During the Militia concentrations in Petawawa in from 1978 until 1982, I noticed most of the Regiments were using 1951 Pattern Web. The 1951 Pattern Basic Pouches were a popular item for those who could get them as they were very practical for carrying C1 and C2 magazines. WWII slings and 9mm Pistol holsters were also quite plentiful and it was always a challenge to get a newer model sling for the FNC1A1 as the WWII slings were too short.