Yup, it's a DA900 alright. It came in various forms; ideally the lenses will be Durst Schneider-Kreuznach 50 and 80mm for 35mm and 6x7 negs, or 50 and 105 mm for 35 mm and 6x9 negs with matching the cams for the Autofocus. Don't forget you will need the MG 500s transformer which is liable to failure and very difficult to replace (rarely seen on eBay) and the 500c controller - not quite so vulnerable and readily replaced with the RH Designs Analyser 500.
Richard