LOOKS LIKE I’LL BE FIXING MY FILES. 
I’m not completely discounting that theory but there are “streaks” on the tops of those bars which are exactly like the streaks where the PPD was cut. If they had used caps the tops would be smooth and not have cut marks. It looks to me that all of those parts were cut by a water jet.
Awesome. This is great. Time to go shopping.
Sander marks. Besides all of the packs have the chunks out of the “beam line” , it just speaks to me of clean up of welding beads. They probably started out as 1 1/4" and were ground down to what you believe is 1 3/16"
Ok I thought of a major game changer for the beam line, why it’s hollow. Remember that these are held on with pop-rivets, pop-rivets need a void on the other side for the rivet to squish into to hold it on. A solid walled hole gives no area for the rivit to grab to.
That’s all making sense and is very probable it’s also possible that they drilled out a space for the rivet head to reside in before they welded on the bottom plate although that’s probably less likely.
So the question is, if using hollow tubes do we go with 1-1/4" or try to find 1-3/16"? I know the lid measures 1-3/16" and visually that’s probably the way to go. The other thing is, solid stock will be easier to work with for a lot of people and even though the original GB1 pack parts were attached with rivets, I personally prefer jpa35’s method of hex bolts. With solid stock there will be a lot more surface to screw into for some extra grip. Just some stuff for you all to consider when purchasing your metals.
Well I was looking over a photo. I’m pretty sure it’s closer to 1 1/4" than an odd ball size. Infact looking over that part you can see a slight taper towards the top.
For what it’s worth, I was cutting some aluminum stock for the beam and filler tubes today with a horizontal bandsaw, and the cut marks are exactly like those pictured. For the PPD, I didnt want to order resin, so I just got a length of 1.25 round bar from the local metal shop, drilled a deep hole on one end for the hose, then chopped it at 45 degrees in the bandsaw.
If anyone here is in the East L.A./San Gabriel Valley area, Industrial Pipe and Steel in South El Monte had all the material listed here in stock. http://www.ipstool.com/
This is ridiculously awesome! Thank you so much for the information! I will definitely be using it to upgrade my pack in the near future.
I just got my metal parts from speedy metal today. To get everything on the list cost about 30 dollars, with another 15 for shipping. The metal cut by them looks pretty good. Plus, Vincenzo330 plates fit and look nice with them too.
It seems like you could also order a few other metal parts from them as well.
The palm rest for the wand
It seemed like stefan’s and venkman’s plan differed on the length. I wasn’t sure which one to go with.
For the ghost trap parts, I used Venkman’s plans.
The ghost trap handle
cut to 5 1/4"
The ghost trap handle base
cut to 4 14/16
The ghost trap wheel base
cut to 2 4/16 long (quanity two)
For less than three dollars you can have a metal ghost trap handle. No more broken dowels. It’ll be great.
Wow. How did I miss that thread? Incredibly useful stuff, thanks a whole damn lot. 
If you’re going the stacking route, it seems like you could have some nice ecto goggle lenses too.
The marks are curved, couldn’t be from a water jet. And by the radius and starting angle, it looks like a 10" or 12" blade on a cold saw. Its the fastest way to make straight cuts. A sander would leave fine lines, not streaks. Those are definitely left when using a carbide blade.
Also the dimples on the edge of the beam line tube look like weld puddles that went deeper than the rest, and turning the weld away would leave the dimples. I could be dead wrong but I don’t think any of those 3 tubes are solid.
Depends on what grit you use really. Circlular streaks could be from a round sander.
Ok I waited for a reply but I guess I’ll just post again. I hate to post two posts back to back.
The " PPD" is definetely made from aluminum tube. It’s 1 1/4" with 1/8" wall. The center is filled with something. Might be aluminum but who knows?
The marks made by saw are unique and different from abrasive wheels no matter the grit..
How are we ever going to find out what the “filler” is?
Just a thought in support of the beam line and filler tubes being tube instead of solid bar… if they’re solid, why weld the base plates on? Why not just drill and tap and bolt it onto the fiberglass? Many of us have does this and it seems plenty sturdy…
Also, the parts in those photos look like cast resin to me… not sure that’s definitive…
Just a side note:
You do not have to buy the metal from Online Metals, infact I encourage you to try to find it locally. It cost me just about as much to send a chunk of metal across the US as it did to purchase it, shipping is a B. I’ve had real good luck locally, I have a shop that will sell me 1’ sections with free cutting.
Lucille 2 is not a B, mother!