Welcome to BGW.
There are a limited amount of Cushman vehicles on this forum but you might be able to find some more information on BGW by doing a search of "Cushman". Use the Google functions here to go back more than a year.
Find attached a Cushman model ID guide. According to this guide, your Cushman should be an "F-2, 1900 lb, 36 volt".
From what I know about these carts, it is likely a slow speed (8 mph or 12 mph max ??) and rated for a 1900 lb load capacity.
For your stated year (1991 ?), your model number (898371) should be followed by another 4 digit number. Is there a model sticker still on the card or a model number on the frame?
I hope that this helps you get started. Good luck on your build
