Reynard 89H vs Swift DB4

Looking for some input as a first timer in FA. I've been shopping around and spotted a couple of prospects but before a more thorough inspection, I'd like to know what questions to ask and what to look for. There doesn't seem to be much info around the web for the 89H in general, which makes it seem like it would be a bit of a head ache. The DB4 is on racingjunk.com (https://www.racingjunk.com/formula/1...swift-db4.html) and the 89H is on facebook (https://www.facebook.com/TheGarageSa...ehZgrraReSePyl). Any info is greatly appreciated.