I don't have details on the 319, but the 316 had a MAUW upgrade with modifications AM2017 or AM1749, utilising the 319 MGB. The Siren hook and frame is the standard Alouette unit, do you have the installation instructions? Make sure that the shorter cables are installed at the front of the fuselage, if it has the cable attachment
2.3.8 of the Flight Manual
