Hamlet LCD Scope, for video signals

I found one of these (pdf) at Goodwill for fifteen bucks. I don't suspect this Hamlet LCD scope, for making video measurements, has much use otherwise, but it was too nice to pass up.

It can monitor 4 audio signal channels, so it may have some utility. Anything else I can do with it?

This looks like a decent instrument, but perhaps not useful any longer? The audio test modes might be useful, but the inputs are 3 pin XLR connectors, so a bit difficult to test.

Lousy pictures. Can;t make anything out. Generally, you can feed one side of the XLR.