For two years now I, a volunteer, have been inventorying our town historical museum containing approximately 2000 objects, not counting ephemera. There are two written inventories with numbers that were written on some items or on cards accompanying them. The numbers consisted of 1 to 500 for the earliest  inventory and 1 to 250 for the later one . I used those two written inventories to assign an overall date of 1963.1.1 etc for items with known provenance and 1963.200.1 for each anonymous one. The next batch of numbers is 1982.1.1 and 1982.200.1 for items appearing on that inventory but not on the first one. Thus any object with a ‘200’ indicated an anonymous donor.
Then I retraced items which were mentioned in our museum reports for the annual town reports to assign dates and donors to those objects. We are still left with a large number of objects which have arbitrarily been assigned 1988.200.1, 1988.200.2, etc as a period of time for which oral recollections by our town historian come into play.
Our museum is open one day per week for three hours during four months in the summer. A second volunteer and the historian and I worked approximately 200 hours this summer applying temporary paper numbers to each item. I hope next summer we can begin applying permanent labels. Books, photos, documents all need much attention for which more volunteers are needed.
I realize this may sound incomprehensible to others but I think it will work for us. I have used an excel spread sheet since I am currently the only one who uses a computer. Excel has allowed me to add extraneous notes, color code questionable entries, track down duplicate entries, etc. I do look at other programs but I think we have enough to do as it is.
PS I have found this site to be very helpful.