There were different part numbers for units with different memory configurations.
For example the A3281A was a K210 that came with 64MB of memory included in that part number. The A3282A had 128MB of memory. There were also different part numbers for configuration sold via distributors, that allowed them to do some mix and match of components. Since the part number is pure marketing and configuration, I'm afraid you have to look at the inside of the front door to tell for sure.
Mom 6