Basically, the large value non-polar electrolytics are being bypassed by 1uf metallized polypropylene ("MKP" type, 400VDC, though 250VDC replacements would work just fine) and 15pf polystyrene (replacement value not critical, just make them all the same if you replace them). The original MKPs are made by Solen, but the Dayton brand from Parts Express would also work as replacements. You can get Bennic replacement non-polar electrolytics and Solen MKPs from Madisound. Personally, I would recap both crossovers with identical parts keeping all values the same. The coils should be fine as well as the resistors, but you can measure the resistors easily to check.
I have a set of CS3.5s in daily use, fantastic speakers with the right amp. A crappy amp just won't do, believe me, night and day with a good amp. I've got a good stock of spare parts for them I've accumulated over time. If you don't mind, take a look at the pics I've posted of an extra crossover I have and let me know if your values are the same.
I do know that Thiel used Dynaudio D28AF and D28/2 for the tweeters and two model numbers for the Scanspeak mid-woofer (mine are 13M8521, but I bought a pair from someone once and they were 13M3808, physically very similar, maybe even identical). I'm curious to know if there were any variations to the crossover. I can't say for sure what tweeter was used with this crossover (probably D28/2), but the mid woofer was definitely 13M8521. S/N is 4331 on this crossover.
