In reply to menace:
> what do you mean by lack of history ?
If they've been damaged in falls, by corrosion, chemicals, been dropped to the bottom of the crag, etc.
Possibly of more concern for 2nd hand climbing items such as harness, slings and ropes, but certainly a concern for metalwork.
If they're new (with tags and supporting safety documentation), then they're likely to be okay. Or stolen...