Your device is a more accurate solution than the stock pressure gauge.
It should give a broader range of the actual pressure than the one on the dash that gives us 3 bars or about half of the actual oil pressure.
And it seems illogical for the stock gauge to show full pressure when there is in fact zero pressure.

In regards to to ferrule crimp: I went to CarQuest and they said that the metal portion of the line would not fit into their machine. The first three guys at NAPA said the same thing and that their machine was the same as CarQuest and had the same fittings. But the next man that saw the hose, took it immediately to the back, cut off the old ferrules saw that the length of the metal line was long enough and had a flare at the end so that the high pressure line and steel ferrule that is used for air conditioning systems would work. He used a hand operated crimping machine and carefully applied pressure several times over many minuets and connection seems very solid.
$8.50 total
The factory upper hose was $127.80
I will report back after 1,000 miles.
A Mercedes shop in the next town uses this method exclusively for years. The operator of the machine is the key.
Ultimately it was the crimp that failed on the lower old oil cooler line that caused the biggest oil lose. The oil was actually misting out and was visible on top of the hood and cowl in front of the windshield. Could not have seen it but for the fact that the car is white.
I hope that this one last half as long as the old one.