A nice fine tooth jigsaw will do the trick. Cuts like a charm.
Make sure to draw out your lines perfectly and stick masking tape along the edge where the cut will be so that the jigsaw does not mar or scratch the surface. A nice filing with a good flat file after that can take off the rough edges and or round 'em out just like the stock items.
An important detail to consider when selecting glass thickness: When you have a post sedan door with its solid window frame, you can get away with as thin as 1/8 thickness glass because it always rides on the rails of the frame. It is snugged into place once the window is all the way up (closed position) and barely shakes depending on how aggressive the lobe of the cam is. More like a quite quiver which I think is pretty cool. It will at sometimes need a little guiding hand to get it to seat up in the rail channel up top during the closing.
It will ride looser when it's down (opened) but not a bother at all.
3/8 thickness will be a little more forgiving and know its trajectory on the rails, but heavier.
Now, if you are permanently attaching the glass (no up or down operation) and with no regulators, then you can save a whole lot of weight and quiver a little less.

Isn't that door from that 68' quite suspect? LOL.
Dam those sneaky covert operatives there @ Area 51. LOL.

I'm feeling a sharp pain in the,,,,,,,,,,,,,NECK......
I have seen this one black car that has poly in the thin version,I would want the thicker version.Is the rear/back hard to install?

Back light is not hard at all in our cars, just patience and the right tools.
It is basically a flat window.Don't wanna damage the original. Worth a $ or two these days.
Lets chat at the end of this week, maybe Friday when the Arts loosen up on my end. I'd like to pay a visit to your garage and talk with the suspect face to face. Suspect being a certain 63' Plymouth that has been bullying all of Long Island. LOL.

Lets EAT!

Gotta be good food and i know there's some good spots out there on the Island.

This Pup here probably takes all awards for light weightlessness and esthetics. It even has sponsorship stickies.
I knew a car like this one back in the day that ran consistent low 11's with a stick.

For your bumper bracket needs check out Lingenfelter Brackets. There Web site give the weight saving going from factory brackets to their lightweight Aluminum brackets.

That is one source,,,,,Ve hav rrrr vays,,,,,,,,,

Thinking about going to a rear glass bumper but not sure on it's strength and obviously I can't push it from there anymore but I'd guess 30+ lbs............

Nope,no pushin!! Play dope on a rope,,,,,,,,

This morning I was sorting through parts from a completed restoration. I came across some old door lock cylinders without keys. I went to my stash and found 2 that already had the end clips and levers removed. I decided to cut all the extra material off and see what the difference was? The first picture shows the cylinders already cut with the pieces on the scale. They weigh 2.8oz. I'm sure with the end clips, levers and tumblers it would be in the 3.5oz range for the pair. The second picture shows just the end caps that I will clip to the doors at just 1oz!!
MJ

So the doors will not lock at all and just be closed?
Good ouncing.

I bought the GTX out of a salvage yard in the spring of 1970 after it had been stolen and recovered. Never had any keys except for the trunk since then! So nice little covers on the key holes is all I need.
MJ

Today I removed my transmission for a pre season freshen up.
So I started on the 2017 weight loss plan!
Today I installed the new aluminum front fender braces from Jeff Ligenfelter! I also had been looking at the old covers for the wiper pivots. Years ago when I removed the windshield wipers I installed some table leg cushions that covered the holes. But now with every ounce in mind I knew I could do better. The old covers shown in my first picture came in at 1.8 ounces only after the one rubber cushion came loose. The new covers installed today would not move the scale from 0! So close to a pound up front today!
MJ

How much did the fender braces remove as I'm looking at them also.

The fender braces with the hardware that Jeff supplies was a weight loss of 11 ounces.
MJ

Picking away you.
Those wiper covers must be the plastic types, since there are chrome metal types as well, but a little heavier by an ounce or two and enough to bump the scale.
I find myself laughing at this, but this is some serious Voodoo science.
Started on the Passenger side light alloy door today with "The Palm Reader" and his magic. I told him it doesn't have to be arrow straight since these were "Factory Hot Rod" parts and weren't perfect to begin with.

MoparJ

How much does that US scale weigh. LOL

Keep it comin.
Love all these hidden ounce riddles within the ranks of various factory supplier items. I bet some F.A.S.T guys are spying on your practices.

Hope to stop at the hardware store today.All the hardware that holds the fenders,grille,headlights,glass bumpers and antyhing else I can find in aluminum.Hope to get the car back in the shop to drop the empty block back in to mock up the headers,mid plate and measure up for a fab aluminum oil pan.
Any guesses how much lighter an alum oil pan will be over the Miolodon??
My Milodon is so old the centerlink hole is round,,,,,,,