Hi tabari !
I updated my iphone with 885 maps using 1.9 Base Kit (find it using forum search engine)
This base kit is a pre-IPA build, and I only needed to add a 885 map activated with TomTom ID device AAHBQ B2XJE.
You must place this 1.9 base kit + 885 map activated on your PC hard disk and compress it with WinZip.
After this, your ZIP pack must be simply extension renamed from ZIP to IPA.
Your IPA pack will be iTunes supported to install it on your iphone (up to iOS 5.x)