Someone pointed out me in private, rightly I would say, that I stated that these fuzes are made in Italy, but without any evidence and I apologize.
So let me explain why these switches are surely of Italian production.
All Italian fuzes derived from English "number switches" are easily recognized by the presence of this bushing.
![Ghiera1.jpg Ghiera1.jpg](https://www.bocn.co.uk/data/attachments/61/61337-ec1324d4fc01da355927d3b0e85e5943.jpg)
which is used to hold the percussion detonator model OTO.
The Italian version of the Switch No. 4, called ST-1 (ST-1 = Strappo 1 = Tripwire Type 1), is recognizable from the body made in a light alloy called zamac.
![ST-1_02.jpg ST-1_02.jpg](https://www.bocn.co.uk/data/attachments/61/61340-cbc4422275736aa5d13afa2af4870ff9.jpg)
Even fuze RP-2 (Rilascio di Pressione 2 = Pressure Release Type 2), version of Switch No. 6, has the zamac body.
Moreover the pivot of the lid passes through a characteristic "hump" formed on the body of the igniter.
![RP2_01.jpg RP2_01.jpg](https://www.bocn.co.uk/data/attachments/61/61342-b4d57bdd9730137de051ecc3fa3491a0.jpg)
I hope to have cleared all doubts.
Regards
stecol
P.S.: For these info's there are no websites, only field or technical manuals ...:tinysmile_twink_t2: