IS 255 Attack still WEapon Cap?

It should have been removed a long time ago. AFAIK none of the item stats are a single byte now since at least a year ago.

Even when items (like the 600 atk Stonetooths) could be above 255, there was code in place limiting them to 255 if a scroll would have otherwise made it higher. I think that's why clean slating the Stonetooths and trying to scroll them was a bad move, they would just drop down to 255 when any scroll worked.

Haven't seen proof that that code is gone cause it's not til recently that you could scroll something over 255 with regular scrolls.

It's possible it was originally there to prevent stats rolling over but it certainly existed after they were stored in larger data space.