It's probably nothing and the functionality the same, but I was upgrading some weapons when I realized about this (sorry for the delay if this was obvious, but first time seeing it in my case):
Basically what you see in the picture, one says Chance: 10-20% and the other 10-20% chance while using skills.
the frist one accures on INSCR weapons and will automaticly be, as it says, the items attribute so on a fire staff it will be a fire wrap. on a water staff a water wrap.
the second one accures on OS items and will ALLWAYS stay +1/20 fire. so if u add it on a water staff its still gives 1/20 fire.
the OS onces look cleaner on items to match. happen to be more specific and some collectors like to smooth out weapon moddings by taking the OS versions.
or Oldschool Cool for example uses this to create his beast of a quadruple Profession staff
There is no difference in functionality. But, they each allow something the other does not. Say, a +1 fire on an earth staff (if you're running some hybrid build and want that for whatever reason). As for "of mastery" it would allow +1 for attributes for which there are no +1 wraps (fast casting and energy storage, for example).
Aside from that, a fire staff of fire magic and a fire staff of mastery are the same thing.
Praise that can be when u say it since u did more research but for me at least (15k gold items ident)
Mostly OS.
So basicly what is true: The Mastery wrap does not drop on OS items(all agree on that?)
I never had one on OS.
And I also never had a <+1/20 Fire magic >( or others) on Insr. (this can accure we heard maybe we get more clarification on that one?)
So I assumed the wrap differences are a OS / inscr difference (based on my experience.) But it seems that's maybe not the case. I will keep my eyes open. Or some one has a
What would happen if the wrap is added to a no-attribute item, as in Q0? or Master of My Domain to a Q0 shield..does it have a chance to raise any attributes?
Woah thats a mind blow question adrastos
from my Guts and logic ( GW not allways follows logic xD ):
when the Item has no attribute then master of my domain or the mastery wrap will have no attribute to connect to and for that reason will have no effect.
I did try a "Master of My Domain" on a Q0 Shield, which apparently does not raise any of the attributes. At first i also thought, if not all, maybe it could raise any "Shield att", as in Com/Mot/Str/Tac, but it doesn't seem to work even on those.
Okay you all made me play the game, shame on you! (lol joking)
here it is:
went and tested it too:
does not add water magic whatsoever
so there you go 
(glad I used up my time today for science 
)
Maybe the mastery upgrade affect auto attacks, where specific ones don't ? Would be worth a try
And I also never had a <+1/20 Fire magic >( or others) on Insr. (this can accure we heard maybe we get more clarification on that one?)
I can confirm of attribute does happen on insc weapons as someone who has been going through a lot of zchest golds of late.
What would happen if the wrap is added to a no-attribute item, as in Q0? or Master of My Domain to a Q0 shield..does it have a chance to raise any attributes?
Some examples were already presented, but here is another 1.
