My old mentor told me I was "chasing clean glass" on a Canon 50mm f1.4, and it bugged me for a month
He meant I keep pulling apart lenses to polish haze when 9 times out of 10 the real money is in fixing sticky focus rings and dead apertures. I tested it on a Nikon 35-70 last month, skipped the element, just cleaned the helicoid, and the customer was happier than the last three "perfect" jobs. Anyone else find out the boring fix pays better than the fancy one?