I made it easy, but it looks like I'll have to make it even easier.

The oft misunderstood attempt at humour in the words in the picture should have made the source evident (IMHO).
Not one person has gone to that source,

Someone on this forum collects aeroplane bits, and has a link to their on line museum containing photos of those bits.
The photo being detail, the section should be easy to find.
Clearly, the diamond level is past.