Help with information on KEF 105.4 classic speakers

Hello all:  I am a new member and this is my first post - hope I get some good information!  I have some KEF 105.4 speakers that I have had since new (time flies, but I think I bought them about 1982).  They are in outstanding condition (with the exception of a "ding" at the bottom front edge of one of the speakers.  They only get played about once a month. I still have the boxes, instructions, and brochure, and have considered selling them, as I have a renewed interest in audio and home theater.  I'm not an engineer, and don't fully understand the electronics, but I happened across some information about how people had "upgraded" the capacitors (?), and other aspects of these speakers.  I am hoping that some expert out there would be able to give me some advice about what might be required to update them.  On the other hand they are original, and I don't want to mess with the insides and get no improvement, as when I do sell them in their original state and I would like them to go to a home that can give them the care they might indeed need.  I live in the San Fransisco bay area.
Thanks for any help for a neophyte!
pretty complicated filters for its day with steep slopes, FFT etc..We sold a bunch of the 104.2 / 4 ...IF you really do want to preserve stock sugest seeing IF you can find a set of spare parts filters and have those modified. Suggest starting with as close to exact value changes as possible but w higher grade caps, then move to bypass and eventually with prof help some real value tweaking..( IMO probably not worth doing)...
KEF was pretty good on parts, filters, kits, etc in those days..would not suprise me If you could find a set of filters..
with a Dynavector Diamond, Souther, SOTA table and CJ electronics they could SING and flat out image anything else we had and we had a LOT of great gear..
Thanks for the response.  I don't know that I want to bring it back to stock IF there are some higher level parts available that would materially improve the speaker's performance.  I'm not familiar with what would need replacing, other than to say "everything".  You have given me an idea - perhaps I can contact/call KEF...
I guess I will need to locate a specialist in the SF bay area.  

You'll likely get more responses to your question in audiokarma's British Audio forum. There is a well documented thread of recapping 105's within, but I believe it's of the 105/2 model. You will have to pay to list them there too.