Hey,
Unfortunately Staves are on a very odd loot scale when it comes to their requirement. You can get Q8 11-21 staves from HM Lockchests as well. Unfortunately, that would be the only item that would be hard to judge the q8 possibilities by. The true chest would be if the chest drops a max dmg item and the unid value is 31-33g, that alone is a sign that the Q8 max weapon chances are there.
I will defer this to the drop calculation expert to confirm I didn't mis-speak. Red Fireball
ANY item of 31-34g value would do the trick - or ANY q8 item from the chest (apart from a staff as mentioned) (which will mean it's in the specifiead unid value range... - the unid value would be the more general and thus more often often happening thing, whilst the q8 would be the more noticeable - I doubt many ppl apart from me would carry all their drops unid to a merchant sorted by their drop location to see their unid values...)