Before working on any tube amp, read aikenamps.com tech button, technician safety button, about not killing yourself electrically. Simple rules but you have to follow them. First off your paper caps may be 30% off in value, but your electrolytic caps that look good may be 100% off. They are aluminum cans filled with water sealed with rubber, and nobody drives 1959 tires anymore. The ones above the deck have circles, triangles and squares for the plus parts. The ones under the deck have cardboard wrappers and a plus on one end.See my posts in this article http://www.diyaudio.com/forums/tubes...ube-amp-3.html about how to cheaply buy new electrolytic caps and install them under the chassis. You can also buy electrolytic caps kits from tonewheelgeneral.com KC or captain-foldback.com in Ontario, using undefined life new cans. These two are also known reliable sources of oil for Hammonds, which you should install soon and yearly thereafter. Two funnels on the TG and dampen the pad in the scanner tray. Don't fill the scanner drum with oil if you don't have a an oil tray and a thread, just a few drops.
The Vishay Sprague orange drop caps are recommended to replace the paper ones because they have long leads and install easily. They also have a defined sound that people are used to. They are expensive because they are made in USA where Vishay actually pays the workers a living wage unlike the *****s that make caps in c****. Hammond originally selected the coil size to match the cap variations, but you are stuck with the coils you have got already. See stefanv.com for an instruction on how to tune your pickups to the cap. I view paper cap replacement on the TG as an artistic decision, as many LP's were made with paper caps on Hammonds mellowed by the lack of highs. The Mallory film caps on e-bay are used and might be okay, or some might not be. The paper caps connected to the tube plates in the amps have had more stress from high voltage, and actually do fail occasionally. Guitar people invariable replace caps in this position in their amps, but goodall is a better cap than many guitar amps used and I have had only 1 failure in a plate cap, and that one had the wax case burned through by the kit builder back in 1961.
If your percussion and reverb don't come back to life after re-e-cap, then check your light bulbs on the reverb. If your reverb has 3 tubes instead of 5, another common failure point is the germanium transistor. If anybody ever pulled a tube out with the power on, the lack of a silicon voltage regulator runs the collector voltage on the Ge transistor sky high and blows it up.
A100's in perfect shape are less strident than leslies, because they only have 12" speakers. Not liking the constant woo-woo-woo-woo of leslies, I'm thinking of putting a 3" car speaker in place of or in series with one speaker in mine to pep up the key-click.
As far a complete rebuild, hammonds have precious metal contacts and probably only need playing to knock the dust off and bring them back to life. More common is refelting to improve the key movement consistancy. See bobmann47's u-tube videos. Occasionally a rectifier tube needs replaced, and long hour units might need the power output tubes. These are available from the organ supplies above or tubesandmore.com or triodeelectronics.com, that also sell the cinch terminal strips for installing the radial lead electrolytic caps under the deck. Minimizing freight costs by consolidating purchases is part of my economy plan. I bought a replacement key from tonewheelgeneral.com and his website has such clear instructions I didn't need to call him. (I don't have long distance phone service). The key mount screws are 6-32 x 5/16" if you drop and lose one. If you are in Canada, use Royal Mail for shipments from the USA or buy from Ontario, UPS and FedEX charge horrible paperwork charges for crossing the border. If you receive at a house, USPS priority mail is cheaper than UPS or FedEx because of the residence surcharges.