I may jump into dirty pond soon but before I need to know about the tools, cleaning agent and lubricants to repair and clean the Isolette II first.
Also, May I know whether the simple shutters like prontor have one mechanism for shutter speeds. If I remember correctly, that advance shutters like one in Rolleicord do have two mechanisms one that takes care of slow speed and the other the fast ones.
Cleaner/degreaser: Electronic contact cleaner such as Dead Link Removed. Isopropyl Alcohol. Naphtha provided it is not used on plastic or rubber parts. Many will suggest lighter fluid which contains naphtha but it leaves an oily residue. Do not use cleaners such as denatured alcohol as it will dissolve adhesives and may remove protective coatings on shutter and aperture blades, lacquer thinner as it will remove protective coatings on parts and may remove some paints or varnishes.
All shutters have a delay gear train consisting of several small parts in a housing and is serviced as a unit. Some have limited adjustment while others have two or more adjustment points. Most shutters adjust the delay for the 1 second setting only and other speeds by swedging or filling the speed selector ring, Compur adjust for the 1 second and 1/15 second settings with newer ones adjusting for the 1/500 second setting also.