Wilbers shock

Been thinking on one of these,,,,,,,,,,,,,,,,,,,,,,,looks to be a lot of shock,,,,,,,,
http://cgi.ebay.de/Wilbers-Federbein-64 ... 5ae09f340c

And TBH why not a set of these too.
http://stores.sportbiketrackgear.com/Detail.bok?no=8782

Why not just revalve the standard unit? costs about 115 Euros!

Stick has one of those, might be worth asking him a few questions.