welcome chris...
the PARTS manual and OWNERs manual are online here...
pick a year, the manuals are HERE...
the sealand 'traveler' is listed in the parts book and all the part#s noted therein .
there is typically a small plastic shroud on the front of the base (held on with velcro)
pull that shroud OFF and the serial number/model will be on the main toilet body.
the main gasket that seals the bowl and holds water commonly develops leaks as the seal dries out.
so u may wanna order that part kit too...
cheers
2air'