I went there too! And, I bought a L1A1. Ther service was good. The location is not good as it is very far away from the MTR. This is the address they gave me when I sent email to ask them for L1A1.
16 /樓
東南工業大廈
青山道611-619號
荃灣
Tel: 24987115
The office hour will be 14:00 – 18:00, every Tuesday and Friday.
Besides the booklet as a gift, they gave me a poster too. Also, make me surprise, they gave 1 yr warrenty ... I bought guns more than 15 years ... this is the first time the seller offered!!