I feel obligated to say,....
It has been my experience in recent years that most of the Moss windscreen parts are dysfunctional non-fitting parts that may only be used with great pain and lots of fettling, and even then possibly poor results. Some problems there are:

Top corner brackets with wrong angle on the pegs, tapped holes in wrong location, incorrect threads, too thick in the legs not fitting inside the frame. Glass that may be too thick, or more likely too thin so it cannot work unless you find rubber packing with non-standard thickness that may work, incorrect relief cuts a the corners, and too small on the perimeter leaving gaps at the corners. Rubber packing strip likely to be wrong thickness. If the rubber strip is too thick(very common), it can be very difficult to assemble the glass into the outer frame. Bottom rubber seal being too thick on the "T" edge, making it extremely difficult to install in the slot of the bottom frame rail. Bottom corner brackets with incorrect bend angle (which might be fixed with fettling). Screw kit with incorrect #10-32-UNF threads. This might be fixed by running a tap through the female threads, but that makes the original parts non-standard (problem if you get good standard parts next time around). The #10 screws also have larger head size that will not fit flush in assembly, causing a gap between mating parts (bad appearance and water leaks). Do try to find correct 2BA screws.

On the flip side, I have had good results with windscreen parts from Scarborough Faire:

Good glass with correct 1/4" thickness and correct perimeter shape. Correct thickness rubber packing strip so the frame assembles easily onto the glass and does not jam or rattle. Correct 2BA screws in a nice complete screw kit, perfectly flush fit with the flat head and grommet head screws. Correct fitting corner brackets with correct 2BA threads. I have not personally purchased their side frame tapping strips, but I suspect they will be equally good. I have not personally purchased their rubber bottom seal, but I tend to trust until proven otherwise.

Last time I replaced my windscreen glass, I took a shortcut. I removed screws from the side frame only to lift out the 4-piece rail frame with glass while leaving the side posts and grab handles in place. That means I did not need to remove the kick panels.

With 4-piece frame and glass on the workbench, remove screws and place them in holes punched in cardboard for reference, so the screws will be reassembled in original locations. I think I only removed two screws from each of the corner brackets.

Using S/F parts, I replaced the glass (new) and rubber packing (new), and all the screws that were removed put back in original holes in 20 minutes. Mind boggling even to myself. the whole job done start to finish and back together on the car in a little more than one hour. I did not change the bottom rubber body seal this time around, only changed the glass and packing rubber.

If you will be assembling it with new screws, do preassemble the six-piece frame with corner brackets without the glass. Then you can trim the screws flush on the inside before installing the glass. Then remove just enough screws to get the glass and packing installed, and put the screws back into the same holes.

Another trick is to use a long #10 screw with a hex nut as a jack screw. Run the hex nut up the screw first. Then run the screw through the frame hole and thread it into the inner bracket tapped hole.Tighten the hex nut to pull the parts together,and install the next adjacent screw before removing the jack screw.

I recon anyone can do this with a little time and patience. You may even do it in less time than it takes to travel and negotiate with a pro shop. Like get the job done immediately instead of waiting for someone else to do it.

Keep in mind that the success and quality of the job is the responsibility of the installer. So if something goes wrong,you will know who to blame (and who might be paying for a broken glass if it happens). But it is a good experience for a lifetime skill set.