I don't know about a PE kit specific to the Amati, but one I was involved in could be helpful, the U-Brass kit for the Revell 1/72 - it has VIIB options and is now a WEM (White Ensign Models) product:
http://www.whiteensignmodels.com/acatalog/index.html?http%3A//www.whiteensignmodels.com/acatalog/catalogbody.html&CatalogBody
WEM 1/72 Type VII U-Boat Flood, Drain and Vent Holes(Reference #PE 7232)
Conatains correct pattern flood, drain and vent holes to fit into hulls of both Revell 1/72 Type VI kits. Price: £16.13 (Excluding: VAT at 17.5%)
AMP - Accurate Model Parts
Fabric Flags, AM Uboat Goodies & More
http://amp.rokket.biz/