"so how many total?" 8 total, all forward. (the real fletcher had 10 in 2 rotating mounts midships)
"do they show in the periscope /uzo-TDC /attack map view ?" Yes!
"if so please post your modifications here : which file, what's added etc..."
(I just got home from along day at work. I wanted to answer you asap. Here is the quick answer in a link below. I will be very happy to post detailed instructions in a few days or this weekend if needed.)
this thread could answer your questions
http://www.subsim.com/radioroom/showthread.php?t=160950
Many thanks to VM for this great ship and to franta for his excellent reply to my questions!