There are several good sources these days for vintage Chevrolet replacement rubber and reproduction parts. Shop around. I found that prices and availability on windshield gaskets varied considerably, and Mike actually preferred the lowest-priced gasket.
A leaky windshield is not acceptable on a rod or custom. On these Chevys, also get and install new wiper tower rubber gaskets, and save or replace those funny rubber-backed washers that hold the lower stainless trim strips. They keep water from leaking into the interior. Further, Mike highly recommends 3M Bedding & Glazing Compound (PN 08509), available at many hardware or auto parts stores, to seal these gaskets. The second choice is black or clear silicone sealer. Do not use hard-setting urethane as used on new glue-in windshields.

At this point, the rubber...

At this point, the rubber gasket was lying flat against the outside of the opening's lip, with the ends of the rope (in the channel) dangling inside the car. Carefully pulling the ends of the rope lifts the rubber over the metal lip at the same time as the rope comes out of the channel. Mike makes it look easy-almost like magic. If you're going to try this yourself, it helps to have someone holding the glass in place and applying gentle pressure from the outside as you pull the rope.

Presto! The windshield is...

Presto! The windshield is installed and sealed in a matter of minutes. The final step was to wipe off any excess sealer that might have oozed out of the rubber, using solvent or a straightedge razorblade if necessary.

As mentioned in the text,...

As mentioned in the text, the lower (beltline) stainless molding fastens with studs on clips that go through the cowl. The cup-shaped washers with rubber inside keep water from seeping through the cowl holes. Be sure to use them, and you might even add a dab of sealer to each.
As I mentioned, you could also get ancillary pieces you needed back in the '50s, such as inside/outside center trim clips and a rearview mirror and bracket, from a junkyard Olds. I actually got a '50 Olds mirror bracket and had it plated before I discovered that '53-54 mirror brackets are almost identical and they're readily available from vintage Chevy parts houses, such as Chevs of the 40's. And although the center post-mounted '52 inside mirror will attach to the '54 bracket, if you've driven an early car with a non-dimming mirror, you know it can be a pain at night. And I know of no practical way to re-chrome a rearview mirror. Guess what? Repro mirrors, in fresh chrome and in a variety of sizes and styles (including day/night) are now available at very affordable prices at the vintage Chevy parts houses. If I were smart, I wouldn't have had to replace the windshield in the first place. But I am educable.
Finally, the latest news on this subject is that The Glass House, besides making polished stainless center clips for the outside windshield trim, has just tooled up to make inside center clips (in plain steel for painting or chroming), as well. You can also order the one-piece Olds glass from them and they will drop-ship it to you. And Mike will even get you the correct '54 Chevy rubber gasket to go with it, if you can't find it yourself.
In the accompanying photos, Mike makes the installation of the glass look easy, even doing it by himself. I would not recommend you try this at home. It's a two-person job, at best. I suggest letting a local auto glass house do the work. But then, I'm not real smart.

When ordering the windshield...

When ordering the windshield gasket, be sure to get new rubber gaskets for the wiper towers, too, and definitely add sealer to them. If not installed properly, this is an aggravating leak spot on '50s GM cars.

Finally, on the outside, you...

Finally, on the outside, you need The Glass House clip to replace the one made to fit the Chevy center bar.

I had my inside windshield...

I had my inside windshield frames chromed earlier, so I got a '54 Chevy clip and had it plated to fit at the bottom (even though it's a little too tall).

A simple solution for a rearview...

A simple solution for a rearview mirror, if you have a more contemporary car, is to use a modern glue-on type, as Mike did in his delivery. He also used a '54 Chevy clip at the top, covered in upholstery material like his inside frames. Right now, however, Mike is making inside clips specifically to fit '49-52 Chevys. They should be ready by the time your read this.

I wanted a more vintage look,...

I wanted a more vintage look, so I got a '50 Olds bracket from collector Marty Strode and had it re-chromed. The stock '52 mirror (left) would screw into it, but then I discovered new chromed, repro, day/night mirrors were available. This one is listed for several '39-50 cars from Cads and Oldsmobiles to Buicks and Packards. There are several other sizes and shapes.

The '53-54 Chevy mirrors are...

The '53-54 Chevy mirrors are very similar to the Olds, with a slightly longer bracket. I bought a "good" rusty one by mail before learning nicely chromed repros are now available for about the same price. Old mirrors can't be re-chromed. To mount the Olds bracket in my '52, I had to trim each molding 5/8-inch and drill two screw holes vertically into the header panel (be careful not to hit the roof). If your headliner's out, make about a 1/4-inch spacer for the third "leg." I just drilled a hole through the material and header, and tightened the screw until it was snug. The day/night mirror will be very helpful for night driving, as will the unobstructed windshield-day or night.