I don't have a 1960, but I do have the 1860 and I can attest to the seaworthiness of these boats.
I live in Southern California and have made multiple 100+ mile round trips to offshore islands on my boat.
When fishing a tournament earlier this year, I made a 30 mile run in 4-6 foot seas with 15-20 MPH wind blowing and the boat ran unbelievably well. Due to the conditions, I could only run the boat at 20-25 MPH, but that's to be expected.
Three other teams made the same run (two in 24 foot Skeeter bay boats and the other in a 29 foot Everglades center console) and the most amazing part was that while our ride was on the rough side we stayed dry, but the guys in the bigger boats came back drenched and said that they got the sh!t kicked out of them...
I've fished on a lot of 17-20 foot boats over the years (Parker, Mako, Whaler, Key West, etc.) and I can say without a doubt that the Blazer is the nicest running boat of it's size that I've ever seen.
If I were you, I'd buy the boat. You're going to be happy with it!