Depending on what chip you've got it may or may not be multiplier locked. Even if it is you can easily unlock it
I had an early unlocked TBird 1Ghz (100fsb) which clocked to 1.2 (12x100) on stock volts completely stable. This was on an ancient early KT133 based board (ABit NF7 IIRC). Couldn't get it any higher though - the machine wouldn't post. Can't remember the stepping but it definitely wasn't one of the fabled AXIA chips. The chip is still going strong (6 years down the line) in my Dad's board. Different board though as the A-Bit went up in smoke
It wasn't stable much about about 110fsb either (partly due to the chipset and partly due to the ram)
You're right about there being two main versions - one on the 100fsb and one on the 133fsb