Bay windows

[nw-modeling-list at nwhs.org]

Dear listers,

I recently acquired a Proto 2000 GP30. With it came a separate package with two bay windows, two sun shades and four "glass" plates, which I thought was very nice.
In "N&W: Second generation diesels" I read that practically all engines were equipped with bay windows. But on several photographs (of different locomotive types) I see cabs with sunshades and those glass plates. For my GP30 it's clear, it had the bay windows, but what was practice here? 
And when equipped with bay windows, were the "ordinary" windows removed or just slid open?
I ask this because for me as a modeler from The Netherlands the use of bay windows etc. is unknown, and I'd like to get it right.
Can anyone shine some light across the Atlantic?

Thanks,

Joost Driehuijs
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://six.pairlist.net/pipermail/nw-modeling-list/attachments/20061016/2d995764/attachment.html