Not sure if this helps since it is in the USA, but I had done some research on rebuilding Konis before deciding to move to coil overs. There is a weblink below.
John,
Thank you for your email request.
These are serviceable. Starting fee is $250.00 per unit pending inspection of internals. If we do find any damage or excessive wear to any hard parts then cost of requisite parts will be additional to service fee. We can provide an accurate quote once we them cleaned, disassemble and evaluated.
We do offer optional restoration services as well, blast, paint, for an additional fee of $100.00 each. These options can be discussed with the technician once upon completion of the evaluation process.
We do have 2 locations, Sonoma, CA. and Hilliard, OH pending your location.
Turn around time for service is as follows:
California = 4-6 weeks from receipt of package
Ohio = 2-3 weeks from receipt of package
Link below will provide you with our service request form downloads for either location.
https://www.performanceshock.com/koni-service-page/
Please advise if you have any further questions or concerns.
Thank you again for contacting PSi.
Jayme Perreira
Performance Shock Inc (Psi)
Dealers and Service Center for all Öhlins, Koni, Penske, Bilstein, Moton, JRZ,
Hyperco & Eibach Springs, Goodridge Plumbing, Fittings and ZF-Sachs Performance Race Clutch Systems
29139 Arnold Dr. | Sonoma, Ca. 95476 | USA
jp@performanceshock.com | www.performanceshock.com
Phone: 707.938.5664 x 105 | Direct: 707.934.4836