Onkyo P-308 recapping/upgrading

Have a nice Onkyo P-308 preamp, she still works great and sounds amazing in its nice warm house sound. 

       Have heard of many shops etc who are scared, and simply reluctant too work on these. I’ve opened it, it is a mess of plastic arms for inputs, and the layout is a clusterbuck to work on. 

     Anyone have any thoughts what replacement parts are used, to better this already great preamp??
 Do I stay with equivalent but higher quality parts?    Would Teflon be better, if used? Just stay with standard but higher quality caps, etc?

Don’t  want to alter the sound too much by going Teflon,  if using Teflon would alter the sound for the worse I don’t know.    Which is why I didn’t buy the McCormack UDP-1 with the Teflon cap upgrade by CJ,...the regular UDP-1 has a much better sound/tone as per almost every review (%95) I have read, I’ve read I think EVERY word and review I could find.  

    Back on track to the Onkyo,......what does everyone say in here?
Take the Chance & have her upgraded/re-capped.. ...or use her as is until “the end”?

      Thanks to everyone for reading my 6th grade grammar/structure. 

Mods, please delete this  

spoke w a good shop, said, not to worry until other 8-10 years or until I hear a buzz, or something goes wrong.  
If you do not want to change character replace only electrolytics, same values, same temperature as originals.
If you want to take a further step get the service manual follow the signal path and replace with better components there.
Maybe when you hear the buzz or something goes wrong it would be too late.