You can get service kits and do the basics yourself. Strip, clean, new gaskets. I would get full kits with new needle valves for the float chambers. If you have been out of the old car loop for a few years, you will find all the prices are through the roof , well I know I do.
Dellorto's are more adjustable than Webers, but there are less places doing spares. My Mate is very good with them, but he is at the wrong end of the country for you.
The only way to re-jet them properly is to go to the rollers anything else is guessing. If it helps I can give you a copy of a Dyno sheet for a mild cam 1400 which would be a jetting start point , but it is on Webers, so you would need to find someone to convert the info to Dellorto, as there is no way it will be exactly the same.