Very nice.
You are probably right about revetmens in the Western Desert (Lybia and Egypt). On the other hand, blast pens were common in Tunisia, Sicily, Sardinia and mainland Italy, as well as in Greece. All major Axis airfields had tens of shelters of different size, as shown by Allied recce and later by Engineering Command surveys.
For example, the Luftwaffe built at Kairouan more than 20 of the small fighter revetments showed above. These were built between December 1942 and January 1943 to accomodate Fw 190s of II/JG2 (source: "Fw 190 in North Africa" book).
Kairouan
Tunis El Aouina
The following two are screen captures of material from the well known
www.wwii-photos-maps.com website
Ariana
Protville West
This last one is about different types of revetments at Castelvetrano airfield, Sicily. The two smaller ones were likely made of stone. But I have no idea about the big one.
