Hi Sebastian,
for picture uploading you might refer to here,
and please see also your private mail 
Hm, the bearing…sadly I don’t know if British Strida dealers these have in stock…
Strida distributor
Cycotic Distribution
Unit 2, 5 Premier Park, Premier Park Road, London NW10 7NZ, United Kingdom
bikerepublic.com
info@bikerepublic.com
- 44 (0) 7768 554931
- 44 (0) 208 400 1248
May I suggest that you simply google for “ball bearing 6802Z” (in case of 100-03),
Google will refine your search automatically, depending on your location.
Example result “ball bearing 6802Z+united kingdom”: