Hi there,
If you just purchased it, i think thats a real good idea. This way you will know the overall condition, and the service shop can establish a service record for you to follow.
Even though its running fine, they may be able to spot something that should be taken care of for preventitive maintenence reasons. With it being 18 years old, it may have some rubber lines that are starting to deterioate and can be replaced before they fail.
Thanks again and best of luck!
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