Depends on the game. Like I said in my post, 3.0 edition stuff is considered cannon in 3.5 so long as 3.5 hasn't rewritten them. 3.5 hardly a completely different edition, it is an update on 3.0's rules. While it may bring up a question or two if the DM is limiting on the resources available, if anything is fair play then there is no point bringing it up in the first place and addressing it may not be worth it. I never said hiding it either because simply you can't. All that information is going straight onto his character sheet (which all DMs should review anyway) and once he's in combat and swinging that thing around, the DM can step in and say his piece if he finds it objectionable.
If the OP's DM doesn't feel like 3.0 stuff isn't allowed or is only allowing things on a case by case thing then sure it would be rude to try sneaking something in, however I don't know anything about the circumstances so I am giving my honest opinion and suggestion based solely on the information given and asked of by the OP.