For the manuals you can look in the Fox-Tango site, they are downloadable from the library.
About the caps: Some look if they have capacitor cheese around the base, but they have also a tough brown stuff around them that Yaesu used to fix the caps to the board.
If you change condensers: Look that you get high-grade caps with the same or higher working voltages and for a higher temperature.
Because modern parts are almost always smaller than the previous ones, it is no difficulty to obtain the right caps.
About the resistors: It is best you get yourself the Service Manual from the library, it has the board layouts, parts list and so, all you need to perk your 901 up.
There is even a Survival Guide for the 901, so enough reading to do.
Hope this helps, saw your entry just today....
73, Wim PA0PGA