On Specific Weapons (D&D 3.5)

[Elfin]

Can you enchant Specific Weapons with further enhancements, as long as they don't exceed the +10 limit?

[Yuki Akuma]

Stuff like Sunblades and Holy Avengers and so on? Sure.

If you mean legacy weapons and unique artifacts, I highly doubt you could.

[Elfin]

I did mean Sunblades and such; thanks for the answer.

[Yuki Akuma]

They're just generic weapons with unique enhancements. You could conceivably make a Holy Avenger out of any weapon.

I had a paladin with a Holy Avenger scythe once. He was a farm boy. It was awesome.

(How you'd do the 'counts as bastard sword or short sword' thing for Sunblades with any other weapon is beyond me, though. Maybe hatchet and dwarven waraxe...)