Hi Simon,
I think you are right about U 995 fairing, it could well be changed in the 1958-1965 period. The photo which confused me is on the right hand side of P115 in Wetzel's book. To my eyes it looks like S 308 (ex U 1202, sailing in the background) has the old mag fairing. And S 309 (ex U 995, moored in the foreground) has the Askania fairing exposed for maintenance. At least that's what it looks like to me, I'm not sure.
However the third image down on P111 shows the old style of fairing. I presume these colour underwater shots are of U 995 but don't know the date.
Great shots in that book.
Cheers,
Dougie