My wife has just got the Lumia 800 and when she goes to the normal Marketplace it lists a load of Nokia apps including Nokia drive.
Would it not be easier to try and make the phone pretend its Lumia 800 instead of a HD7 so that you can just download the app directly from the marketplace?
I have posted a thread asking that question before seeing this...
HTC HD2 - ROM: WP7.5 BTTFv2 build | SPL: HSPL2.08 | Radio: 2.15.50.04
HTC TytnII - ROM: Ultimate X-2 V10| SPL: 3.34 HardSPL | Radio: 1.71.09.01
HTC TytnI - ROM: Schaps 4.31 Full | SPL: 2.10 olipro | Radio: 1.54.07.00