The lock bolt is in a deep recess requiring a long socket head allen key to access it. As the bike shop had to purchase that tool it is therefore reasonable that they charged you for the job, given also they are paying for the mechanics time.
If the seal is leaking again there are several possible causes;
1 ) Pitted or damaged tubes that in turn damage the seals
2) 20 years of fork bushing wear, more wear equals seal distortion.
3) The recesses in the outer tubes that the bushings sit in ( just under the seals ) could be flogged out.
4) Excuse me for saying so, possible poor installation. Proper suspension specialists have special installing tools that instal the seals squarely and evenly without disortion. Driving the seal in cold is also a no no.
5 ) Low quality aftermarket cheap and nasty seal? There are more than a few out there in the market.
6 ) Bug spatters on the chrome legs, contact with heavy duty cleaning solvents that harm the seals ( another big no no ) etc
7 ) Not replacing the first line of defence, the dust seals. These do wear out.
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