Interesting about the surgical tubing thing. There was a pair or 4060s that re-sold in the yard sale here last year which I understand were custom built originally for a DPA customer that asked for a 4060 which could be used like a regular mic, and became sort of a prototype for the 4090. Each had a 4060 capsule at the end of a thin drinking straw sized tube with the XLR adaptor at the other end. Basically a 4090 without the normal diameter tapered body.
Intersting to hear your take on the 4007. Never seen one myself but would love to try a pair someday.. all it takes is money. Finest sounding DPAs I've been exposed to were the high voltage supply subcards (don't know the number), transistor based and transformerless but required special DPA power supplies.