Well, your bike would be the best source of specs!

There is very little information available stateside regarding Batavus bicycles (if, indeed, you are stateside!) I have an '85 Batavus Competition frame, which I was able to identify by contacting the existing Batavus bicycle company: http://usa.batavus.com/

However, the company was sold in 1986, so while they have some old brochures, detailed information on past models is scant. I found the current employees very helpful (via email), but your mileage may vary. They sent me some scans from the Dutch catalogs for my frame.

There is one other thread on BF specifically regarding a Batavus mixte. Here it is:

http://www.bikeforums.net/showthread.php?t=261838

You may want to confer with the original poster, and you may want to contact s70rguy (if he doesn't check in here first), as he's the closest BF has to a Batavus expert.

Good luck!