need help on dynakit st 35

Sounds like a # of problems, You probably deduced the need for new tubes, and it sounds like the need for new capacitors. I would also be checking around for cold and loose solder joints. Check the values of all components if you can, after 40 years they almost have a right to not have held their values(I know I haven't). Won't get too expensive as long as the transformers are good, you could do a lot of good bringing it up to speed for less than $150, and a nice little amp when working properly

Check the older threads, the st-70 comes up time and again and there have been numerous posts detailing the various aftermarket restorations/upgrades for the unit. If you're going to start doing internal work you might want to look at all your options.

Sorry, I may have mixed the st-35 with the st-70. I don't know how different the two are soundvalves.com and avahifi.com both have kits for the latter. Check around though. Some of the tube places may be able to help.