Chet,
please allow to let me coming back to your topic.
Founded on what Al has profound stated (once again :-) ) with respect to the ISO Standards for Welding Symbols, I have tried to find out what the Italians may perhaps use to draft their drawings.
In my assumption I guess they should - as well as all the other European Countries - use the Euronorm Standards for Welding Symbols and their representation. These standards are intermediately in a large extent conform to the ISO standards.
Therefore I have tried to find some particular information about the German Standards which could be - in my opinion - identical to what the Italian company has used when they have passed on their drawings to you.
In Germany we have used at that time the German Standard DIN 1912 for Welding Symbols. Due to the European Community and their efforts to modify all national standards for implementing European ones we are meanwhile using the Euronorm (EN) Standard EN 22553. This standard treats the use of welding and additional symbols in engineering drawings on a European level.
What I have found in my "library" was not so bad, but as you probably can imagine it is all written in German language. Thus it is most likely "useless" for you - as far as I think.
However, I sat down today and have tried to "modify" the information what I personally have available, by using my picture editing program to pass on some details to you. It was sure extremely time consuming (thanks to my family for their patience with me) but hopefully it will make it possible that your inquiry can be answered in a sufficient amount. This would be my largest pleasure after I have finished now.
I have prepared some jpeg's which I will embed into a pdf. By reading the files I am certain that you could compare if this what the Italians have used is similar to what the EN 22553 Standard states.
Some further details for the correct understanding of the jpeg's I would like to list here afterwards. The first jpeg (Euronorm_22553_General_Instance) is to be read by knowing the sense of the numeration (1... 7).
Designation to Type of Weld and Dimensions:
(1) Type of joint
(2) Symbol of Joint + Addenda Information (see also the Euronorm_22553_Basic_Symbols and Euronorm_22553_Compund_Symbol.jpeg)
(3) Length of welding seam, Number of single seam lengths
Additional manufacturing descriptions (following the "gab" or the "tail" of the "Arrow line"):
(4) Welding process according to EN 24063 (ISO 4063)
(5) Quality Classification according to EN 25817 for steel and EN 30042 (ISO 10042) for aluminum
(6) Working position according to EN 26947 (ISO 6947)
(7) Filler Material according to the specific Standard (e.g. EN 440 for GMAW)
The single descriptions on the "Arrow line" are to be selected by diagonal slash. What you can also see in the Euronorm_22553_General_Instance.jpeg is a rectangle (containing an A1) this is for describing additional details e.g. production data etc.
The most complex in the European Standardization is the fact, that one has the opportunity to use four (!) different options of symbolic representations for showing only one (!) welding detail, as to be seen in the Euronorm_22553_Symbol_Representation_4.jpeg. Therefore it is recommended to use only one of those four options to draft the engineering drawings within one welding job.
I guess nobody knows why this kind of procedure (four different options) has been decided by the European Community. It's a bit funny but this is Europe at its best.
Nonetheless, I would be very glad if I could have helped you with that...
Best regards,
Stephan
P.S. I hope that I have translated everything into an understandable terminology...