In the past I always put 500's in my Strats just to keep it flexible... I seriously NEVER had them quite open all the way, just a little glassy.... Now I play with adding resistors of different values until it's tuned to my desire... Usually ends up around 300k total resistance... Try several options and feel it out... Good luck!
300k is not a bad call in all actuality. Such a choice can result in the amp eq being able to have some control. IMO, not a bad choice at all.
330k pots and turn the tone control down until you find the tone you like. This way you will have some extra treble on tap in case you want it (just turn up your tone knob).
Why throw away the treble with a 250k pot and not be able to get it back if you want (except by taking the guitar apart and replacing the pots again)?
Keep it simple and keep your options available.
If it worked that way I'd agree with you (that was exactly my reasoning when I was doing my rewiring). Your pickup sees the same load regardless of pot position. Someone explained to me that this is because volume pots act as voltage dividers rather than variable resistors . . .
In actuality, it does work this way. With 330k - 500k pots for vol & tone. Then if your guitar is too bright, just turn the tone pot down a bit. That's why it's called a tone control...it controls tone by varying the amount of treble (dependant upon cap selection). Leave the tone control set to where it sounds good for most of your music, then just turn it up or down further as desired to add or remove more treble frequencies.
I just noticed you're from Scarborough. I lived in Toronto back in the early 70s (a bit before your time) and knew a few musicians in Scarborough. Neil Young and Lighthouse did some recording in toronto while I was there. Mike Brewes was a very talented keyboardest, etc. who played in my group back then. A real coincidence, I know, if you were familiar with him.