Mistakenly removed dtproperties, now I can find my diagram

I am currently testing SQL Server 2000 Evaluation version.

I created a diagram with the diagraming tool, but in the process I mistakenly deleted the system table 'dtproperties'. I have a backup of the database, but the last time I restored it, I lost my diagram (and had to do it again)

What I've done to try to get it back:
I have another database with the old table schema, and I tried to enter all the values it that old database's dtproperties into the recent db's dtproperties, but that didnt' work especially since I didn't know how to copy the lvalue column.

How can I restore my diagram?I believe no chance to retrieve the diagram as you're using EEE.