Also, when we took out the beadboard patch underneath the window, we found that the outside hole had long ago been patched with wood siding. So that eliminates my worry about when/if we take off the aluminum siding there being a big hole under the window to deal with.
Darwin, Ken and I brainstormed and decided to build a shallow built-in bookshelf there under the window instead of trying to patch the opening. The shelves, which will be right between the tub and toilet, will be perfect for holding excess bathroom stuff (my 10 scents of shower gel, for example) and "reading material," the menfolk add.
Anyway, I'm very relieved at this development. Thank goodness we figured it out before I bid on the antique window with privacy glass on eBay! It was very cool with original hardware, but I wasn't too sure about the privacy glass.
The bathroom window is shaded by a large fig tree and is in a private spot anyway, and I've already been daydreaming about relaxing in the tub while gazing out the window. Gazing at frosted glass? Still fun but not quite as fun.