Urgent Question Re Window Replacement

["Tom B." <gringo9779@xxxx>]

Howdy! Am new to this Group; just brought home, 1450m. from 
Wisconsin, a 1970 31' Sovereign Land Yacht [should I be seeking a 
VINTAGE Airstream group?]. Have had many trailers over past 34 
yrs., but this is my 1st AS.
Enroute, my front left [NON-opening] window took a rock, 
shattered, blew glass all over the sofa-bed & LR. There are only 
solid head rivets on the outside metal frame, which by browsing some 
AS sites, I see requires special [& expensive] tools to replace.
Inside, the window is surrounded by a plastic frame, held in 
place by the more-common hole-in-middle rivets [which I have the 
tool for, and experience with]. I've emailed owners at several 
sites about this, but no one's answering, and it's pretty urgent I 
get the window replaced quickly [live at 6700' elev., no cover for 
trailer, winter's arriving early!] My question:

If I drill out those rivets on the interior plastic frame, will that 
give me access to replace the pane?
[Which curved Corning Glass I understand is no longer available, and 
I'm thinking Lexan.]
......................
Also: the reason the window was vulnerable was that previous owner 
somehow broke the rockguard panel, but simply removed it and saved 
the frame [which I brought home in my pickup bed]. He told me that 
replacement cost was $300 to $350, but add another $300 for freight -
youch! So my 2nd question:
Is there any material I can get locally that will conform to the 
rockguard [with it's slightly curved ends] that will protect the 
windows in the future [and, of course, look reasonably good]?
......................
Thanks. I hope to get up to speed on Airstreams quickly [Hey! I've 
got Traveling-Plans! :> ], and I Do have general RVing & boondocking 
experience I'm very willing to share.

Tom Bokalosky, Mountainair NM