If you're doing a lot of repair work, you'll run into situations where there isn't the time nor money in the client's pocket for a new nut. For instance doing work on cheap instruments at a festival...as I just did...and a $15.00 quick fix gets the clients playing NOW, not next week. A lot of folks have ukes worth barely more than the cost of making a new nut. It's all very fine to get all high an mighty about what one SHOULD do in terms of repairs...as though all instruments were worth the bucks...but the reality is that often enough a quick, reasonable, even somewhat temporary repair is the RIGHT thing at the time. I did both bone dust/superglue fixes as well as shimming nuts up at Strawberry last week for very, very happy clients. They knew that the best fix would ultimately be spankin' new string nuts, but for on-site and for something that would last at least three or four months, they were really happy.
One way to really turn off potential long term clients is to go all highbrow on them and insist on work that is beyond their budget or that is just not appropriate for the quality and value of their instruments.
And this is one of the reasons I do do lutherie on-site at some festivals...it keeps me in touch with the reality of what people are playing and keeps me flexible to their needs. It's like knowing when to just go ahead and use superglue to fix a crack and when to fire up the hot hide glue pot. I think it's perfectly fine to build at one consistent level, but to repair rather flexibly. Not all of these instruments are future valuable vintage pieces, yet they are tools of musical expression and joy to their owners.
This year it was mando city... I did a partial refret on a nice Gibson F5-L, did a full refret...and nut shim...on a Kentucky F-5 copy, a fret mill on a Gibson F-5G (varnish finish...all crackled), and turned down a refret on a 1914 A-2 because it didn't quite need it yet...yes, the frets were divoted like mad...but it didn't fret out or buzz, so I told the new owner to just live with it for a few months and then do it. Also put railroad spike capos in three 5 string banjos, attempted to reglue about a half dozen loose top braces in a Korean Ovation double neck..one of the worst pieces of s..t I've ever had to work on, and found the most f'd up 1942 Martin I've ever seen...a 00-15 with the mahogany top painted off white to emulate spruce...and done a long time ago...multiple horrible cracks "repaired" with Titbond smeared all over, a Brazilian rosewood fingerboard once painted black with the deepest fingernail divots I've ever seen. It's a guitar that you could easily sink $1,500.00 worth of repair into...and it would be...maybe...an $800.00 guitar. Oh, did I mention it needed a refret? The guy dropped it jumping over a stream and the top was separated on the lower bass side bout. I glued it...