At 30 years old ANY sailboat's standing rigging should be considered suspect. I have seen 30 year old Tartans that were beautiful . . . and six year old Tartans that had problems. In 95% of the cases of rig failures for most any sailboat it is the owner and lack or maintenance or mechanical difficulties (i.e. lots of jibes that allowed the boom to smack the rigging hard. Improper size clevis pins in chainplates. FAilure to coat the threads with lanolin or similar, etc.)
Have the boat surveyed. That will protect you somewhat and should bring the worst faults to light. Moisture in the deck, hull, blisters, wood rot. None really dangerous but tres expensive to have a yard correct or time consuming to do yourself.
Catalinas are not bad boats. I owned a 34 for six years (the one in my avatar) and it was a peach. I wouldn't have taken it around Cape Horn, but for my sailing it was ideal. They are just not finished to a high level of interior cabinetry and jointery. Not bad . . . for the price. I caught a couple of factory goofs that a Swan or CS probably never would have had, but nothing serious.
Charlie P. P31-2 #80 CATNAP
To travel hopefully is a better thing than to arrive - R.L. Stevenson
I suspect that, if you should go to the end of the world, you would find somebody there going farther . . . - H.D. Thoreau