Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
It actually looks like one of those goofy multi-position (ratcheting swivels) ladders that were popular a few years back.
Like I mentioned a little earlier, it may be a ladder "liberated" from another type (or source) as it doesn't seem to be the crew access ladder that's typical equipment for the Ju88.I'm not sure that is a ladder in the picture at all!
The usual ladder was a standard 8 rung affair with two hinges allowing it to be folded and also used in different configurations.
Cheers
Steve