If you do not have a salamander at all, go with the salamander. At 1000 points, I think that is the best way to go.
Yeah you don't really need an old blood until you want a carnosaur anyway. Scar vet can provide combat kills for a lot cheaper than the OB.
I agree with everyone else. Get a salamander in the fight. Scar-vets are awesome. No sense in having an old-blood in a 1k game.