Question on Viewing Oil Trough Oil Level.

I've been working on my 29 exterior, interior, wheels, etc. The engine hasn't run has since last summer, sitting on in running stand ready to be put into the car. I was cleaning the engine off of dust and doing a visual check as part of getting her ready for a startup.

I noticed the red top'd oil gauge which was about 1/2 inch from the top of the glass last summer has risen into the screw cap of the glass and become invisible. I was wondering if the troughs had drained into the sump. Trying not to remove the sump pan unless I have too. Is there a way to use a pipe scope to look at the troughs for sufficient oil levels. I know the trough pan develops holes.

Thanks for any advice