question about gold items

If I find a gold sword, lets say 8 req, 15-22, with 15^50 built in.

it has lets say... a vampire mod and a armor mod.


Can i add these 2 things to it to make a.
sword pommel of fortitude +30
sundering sword hilt 10/10




15-22 req 8 swords
15^50
10/10% armor pen
+30 hp


or does it have to spawn like that?

it doesnt have to spawn like that. the only thing you cant change is the damage, the req, the damage modifier, and the color. also on fiery dragon swords and icy dragon swords you cannot change the hilt.

so your saying I could add the 2 uber mods, and it would erase the 2 bad ones?

Yes. But doing so just to resell isn't always a good idea. Buyers pay for the item, not the mod. Most collectors already have "their" perfect mods anyway.

If i get that longsword from a collector, with 15^50


can i add sundering and fortitude to it? so it has both ?

Yes you can add mods to collector items. The only items you can't mod are greens and I believe some quest reward items.