What is a Kees Krawler 'tractor' sprinkler worth and where to find parts?

Question:I just aquired a Kees Krawler sprinkler from ym grandma and its really cool. It's a little rusty, but I used WD-40 and pen. oil and got everything turning like new. I want to use it, but want o tknow if I can still buy parts for it and what they are worth. She has 2 more I can have if I want them. Thanks.

Answers:
I couldnt find parts but here is a link from msn search that shows them for sell from 29.00 to 52.00...home depot sells new ones still, but is great to have the original ones!