It looked pre 7.5ish when booting (if my fuzzy memory serves correctly) but I'll try that. I got the same bomb system error screen (with no text in dialog box) when holding down shift. I'll try the space bar trick shortly, just got home so I need a little couch time! Luckily I do have that external HD and plenty of external CD drives to help things. The startup chime seemed like it may have been a little weak. Been a while so not sure if it's perception or fact.

Recapping is a skill I need to work on. I'm willing nothing has ever been changed out on it. I'm willing to bet I'll find some Macs that need recapping when I start testing my big stash. As you said, even if they haven't failed it's still smart. Better to get them before they blow for sure.