If it's anything like the quality of my 1982 Alpiniste 65L sac, then it will last the owner many years of use.
The Alpiniste model was made of a slightly heavier material than your Trail 25 sac, almost identical to look at, but the weave and density of the material was more like a heavy duty canvas.
it's the very same model used by all the high altitude climbers of that period, Messner, Bonnington,Doug Scott, Dougal Haston, Don Willans.
Look at any Everest photograph from the early 1980s and the sac is somewhere in the photograph.
I recently found my receipt for the Alpiniste sac, £64 from Crickhowell Adventure Gear in Brecon, that was good money back then, especially when the Berghaus Trango Extrem Gortex jacket retailed for £124.
Ive only used it once, when i helped out marshalling for a Welsh 3000 charity event years ago, i had to carry just about everything, including emergency rations for competitors and emergency shelter for myself.
Really comfortable on ones back,and it has a very impressive waistbelt and three chest harnesses, but the sheer weight of the extra kit almost crippled me.
Karrimor gear back in the 1970s early 80s came with a lifetime warranty, just a shame the company went bust, because Sports Direct may own the brand name, but the quality of the gear is a joke compared to what it used to be.
Recently i was looking at the sacs in Cotswolds, their tissue paper thin in comparison to the sacs of thirty years ago.