Thanks, 1 Eyed Jack - none of what you said has been previously mentioned. This is a tricky business, huh? I'll have to try it out that way and see what happens.
Just as an update: I went to buy the GP 100 yesterday and all they had was a blued version which I promptly turned up my nose at.
I also handled the SP 101 with a 2" barrel and didn't like it much. Anway, they ordered in the correct GP 100 from another store, so I should hear from them sometime this week.