Hard to say really, do you know if everything is still standard on the bike, like down pipes, end can, air filter?
If they are then at that mileage and the fact that you're saying it "runs lovely" then i would be inclined to not try and fix what isn't broken.
In the same breath, if you're anything like me and like to know things have been done properly and with a bit of TLC then you sound like you want to really scratch that itch.
It's not too difficult to do if you're confident enough and have the right tools, i personally use the Morgan Carb Tune kit and it works very well with a bit of perseverance.
Take note of the tools required on this link for the job, especially the long Pozidrive screwdriver to adjust the carb screws as they're a bit buried, but on the right side screw i actually use a small 4" flat blade screwdriver as i find it easier to access it.
As a note for anyone else, to do this successfully you need a fully functioning TPS unit (yours should be fine) and a clean air filter, otherwise problems with either could end up with you unwittingly setting up the carbs wrongly due to false readings.
I'm not sure of the price of a Morgan Carb Tune these days but i do know it makes economical sense to buy one rather than pay for someone to balance your carbs, as you will use it again then it will pay for itself within two uses. I just bought a used one off Ebay, that looked like new when i received it.
Presumably the introduction of fuel injected newer bikes is why people tend not to need them anymore.
http://foc-u.co.uk/index.php/topic,91.0.html
