When I first started out I was like many others in that I wanted to continually raise the bar on my "PB". Given the fishing climate at the time, everyone kept and sold most of their catch, thus everything got weighed as a part of doing business....you got a "slip" with the "official" weight on it.
I always carried a brass chatillion in my vehicle because many of my fish went into the back doors of restaurants and they relied on my scale (for better or worse) to determine the weight.
Once I stopped selling fish to restaurants (early 90's) the scale stayed at home as most of my fish were released if I couldn't sell them. The commercial fish were coming in bigger numbers for me by then because I had my own boat. It became impractical to unload big numbers of fish at restaurants(also illegal

) thus I took everyting to Chatham fish and lobster and got paid wholesale.
Past experience has given me the ability to guesstimate pretty well, and if its a really large fish I might keep it for bragging rights, documentation, tournaments, or consumption. I have no problem killing one big fish here and there.
Guys who made claims without producing weight slips were often looked at with suspicion, and in most cases (even today) its still the case.
I do carry a scale in my vehicle just to save me a long ride to an official weigh station if I get lucky enough to land a substantial fish. If the scale says its close to a weight I might want to get certified, I will then go to a shop and get it officially weighed.