Replacing a lost toolkit

The seat bag toolkit went missing on my bike after 30-odd years.
Unfortunately, I noticed only after getting a flat tire 8 miles
from home. As penance for my inattention I elected to walk, despite
half a dozen offers of help from other riders and one motorist. The
exercise is one I'm not eager to repeat 8-)

Beyond the obvious (tire levers, patch kit and spare tube) what have
folks found worth carrying to fend off routine trouble? My kit
acquired quite a bit more, including a chain tool, spoke wrench and
freewheel tool, along with hex keys. I don't think any of the first
three have ever been useful on the road, but they don't weigh much
and they're far easier to find if they're on the bike. Has anybody
ever had use for them, or other "shop" tools, on the road?

Suggestions for a seat bag would also be welcome. For the moment
I'll put the tools and spares in the pannier baskets, but that's
dangerous as they can be removed and forgotten. Much better to have
necessities permanently living on the bike.

Thanks for reading!

bob prohaska