"Now I didn't do enough tests to get the full spread only did 9 single hit's" - As I mentioned before, the higher your base damage, the more difficult it is to be sure that your sample values cover the full range with a given number of attempts. However we can at least see if any particular threshholds were crossed.

"I hit a max single hit for 490" - This, however, gives us something to work with. Extracting the 1.05 multiplier from 490 means pDif damage had to be at least 467. 467 damage on 224 base means a pDif multiplier of at least 2.085 (2135/1024).

If we consider that this attack multiplier is applied in the same phase as other such multipliers (ie: before cRatio is calculated, similar to other weaponskills), we need to back-calculate the cRatio that could support that max pDif. The max pDif addition to base cRatio is capped at 384/1024 (probably; not completely pinned down) for cRatios higher than 1666/1024. 1666+384 = 2050, lower than our required max. Therefore we can consider the max pDif to be using the capped version, and the actual cRatio to be 2135 - 384 = 1751/1024.

Going from 1449/1024 to 1751/1024 is an increase of 302/1024, and would require a multiplier of at least +20.84%.

"Weakest being 275." - Would seem impossible to draw any conclusions, but can make some guesses based on my older formulas.

275 damage on 224 base would be ~1258/1024 pDif. Min pDif is calculated as an offset from a (factor*cRatio) value. For one-handed weapons, estimates were factor=1.13, offset = -711/1024.

Working backwards, 1258 + 711 = 1969. 1969 / 1.13 = 1743. 1743 is remarkably close to max pDif value of 1751, though since it's lower it's suspicious.

The max pDif that could result in 275 damage is 1261. Using 132/1024 as the multiplier on 1751 (which we know is a min value for the cRatio) we get 1751+225 = 1976. 1976 - 1261 = 715, which is a possible offset for the min pDif value (min pDif formulas were not completely nailed down, and I haven't restarted the testing yet).

20.84% is 213.4/1024. Rounding up to the nearest interval of 4 gives us 216/1024.

719 att plus a 216/1024 attack boost gives us +151 att, for a total of 870 att.

Aside: I should also add a query as to how you reached 719 attack. That seems higher than reasonably achievable without food or buffs like Berserk. If any secondary buffs were in play, that can affect the final reasult, since percentage attack buffs stack additively (eg: 400 base attack with two 25% attack buffs would give you 600 total attack; if you didn't know about one of the attack buffs, it would look like it increased from 500 to 600 attack, or just a 20% boost). If that's the case, all of the above calculations are thrown out the window and we have to start over again.

In any case, the above calculations for min and max don't quite sync up, though they're quite close. It's possibly a 21% attack boost, or possibly a 25% attack boost applied to an undetermined base attack value.