Older Snapper riding mower - any good ?

Question for people with lots of riding mower knowledge/experience - I just was given an old red Snapper rear engine riding mower model 30085S with 8hp Briggs motor, electric start, looks like maybe about a 30" cut, not sure. I don't know what year this is. Can anyone tell me some things about these riding mowers- Are they good, reliable, junky? Quirks, things to watch out, go wrong? Are they better or worse than say a Murray (MTD) or Craftsman front-engine riding mower? How reliable are these little snappers? Any idea what year this might have been made based on 8hp and model 30085S? (SN is 53070437). One odd thing - the oil filler cap is just that, a cap only. Where/how do you "measure" the oil fill level - how can you tell if you need to add oil or how full it is ?? I can't find any dip-stick. Just trying to get a feel as to whether this tractor is a good one worth keeping or a lemon/junker that will give me major problems pretty soon. Thanks !!