Just examining the brace, it isn't bowed at all. I do believe the crack has increased over time. I checked my notebook, but didn't record when I first saw it. I'd guess it's been expanding for 4-6 months, though that's purely a guess.
I've got a DIY AHS-fashioned light "holder". It's about 50% of the width of the tank. When I do tank maint, I push the fixture almost all the way to the wall, and frequently the 55w CF in the back is likely over that portion of the brace. It is quite a stretch for me to scrape GSA off the bottom front of the glass, and at times it takes quite a bit of pressure. I keep wondering if between the heat and me 'leaning' into the front glass at one time or another if that might have started the fissure. I guess if the problem recurs after I replace the current rim, then I'll have to reconsider my ways
By the way, the new rim with $5 for shipping is running a bit over $22, and they state it'll be here in 2-4 days. If they actually make good on that delivery, I'll be a pretty happy customer! Though I should wait until I've actually pulled off the rim replacement before I decide for sure
Thanks for the thoughts, Hoppy,
Oh, and AndyT...you're not going to give me a guarantee on that recommendation