My Bump with the stays and hip belt and without any other accessories weighs 2.5 lbs.
Keep in mind that the bottom of the pack and most of the shoulder straps are full spectra material. Nearly indestructible. The rest of the pack is made from Dyneema grid, the smaller squares, meaning more Dyneema threads. I usually use the water bottle pockets on most trips at a minimum, which adds another 5 ounces. The hip belt has two buckles and pretty thick foam. Shoulder straps have thick foam too. The pack has a foam pad inserted into a sleeve in the back of the pack, I never take it out, put it can be removed. I could probably get the weight down to closer to 2lbs, while keeping the hip belt and stays, but I can save 8 ounces by reducing other gear.
The stays on my Bump are probably half as wide as those on my LBP, which can carry a lot more weight. The LPP is full Dyneema (not the cuben composite dyneema), which adds a lot of weight and is made to last a very long time. The LBP also has some heavier Spectra on the bottom of the back and the shoulder straps — a bit heavier (robust) than the main pack body.
If one wanted to get one of the old “summit packs” a good place would be to check out some of the forums that are mostly focused on the NW part of the country, or maybe Craig’s List in Seattle. Seems like McHale packs are very popular in the Seattle area where Dan lives.
When Dan built my Bump, it was a new model for him, however what I requested was something he had already been toying with. Apparently he had already built a prototype, which might have been the demo he sent me — or perhaps he built the demo specifically for me, with the intention of adding it to his inventory. I use the Bump on most of my shorter trips.