Just hope it's not a case of 'you get what you pay for'
He's had very good feedback on the forum over several years, probably not a long job if you have spent years stripping and rebuilding them.
It's actually not a long job if you are doing it for the first time. Carbs arn't terribly complex and if you use a Haynes manual and take a little care, removing jets, slides etc and cleaning them with the right solvent before replacing them it's a piece of cake. The only difficult part is setting float heights and pilot screws on reassembly sometimes but that's hardly rocket science. All in the Haynes book.
You only need to ultrasonically clean carbs if they are very badly gummed up, a solvent and a can of compressed air is enough to clean up most carbs even on bikes that have been laid up for quite a long while.
Some might throw their hands up at even attempting a carb strip but if you are somone who does other jobs on your bike it's not beyond you to have a go.