Didn't think they made an 87 320E ?? 300E was the norm, the 3.2 liter motor (104) came along in the 1990's. Was still a I6 like the 300E.

My impression of a stored MB is not a positive one. Why would anyone stop driving a usable car of this type. Only consider it after finding out WHAT IS REALLY wrong with the car. A water pump is DIY for less than $200. Instruction can be found on this board. OR, dealer repaired for $400 or so. But, I suspect that is only one of the repairs that may be needed. MB's do not do well when not driven for more than a few months. (perhaps no car would unless prepared for long term storage)
Luck to you tho....
DanielW