Here's a free pattern from Ravelry.
http://www.ravelry.com/patterns/library/oval-pineapple-doily

That one's beautiful but it's only 8 X 12. I found a pattern on ebay and sent for it.It's 21 X 28 I think.
Thanks for the help though!

Can you find an oval placemat pattern that has a center section that you could repeat several times to get the length?

I have about 30 crochet magazines that I inherited from my Memere - many the kind that have tons of doilys. AND I have added to the collection from thrift stores and yard sales. They are out there. If you really are going to do that type of crochet, I suggest you start haunting these places. Another alternative is to ask older women that you know if they have any that they would let you have or borrow to look at and copy patterns from. If you lived near me, I'd be glad to share, in the lending sense. So start with women over 50 because we may have some of the really old ones from OUR grandmothers!
Good luck. If your ordered pattern doesn't work out, email me and I'll take a quick look at mine!
Kathy