extruding multiple surfaces and merging them together as one

Greetings,

I'd like to ask you for help with problems.

My diploma thesis is engaged in the production of the prototype mouse, I created a physical model - the 3D scann (1,200,000 points) -> stl -> edited it in trial version of geomagic -> exported as .iges -> opened in SolidWorks 2014

I need to extrude "pseudo"flat circumferential surface (which consists about from 260 small surfaces) - every time I try, I fail - with knitting, add connection profiles and other features results are same - nothing, nada, nai.

The extude i would like to make is just adding 1mm with a result of a continuous flat surface.

Iam adding models in sldprt and iges:

http://leteckaposta.cz/317103740

http://leteckaposta.cz/835324852

Thank you for help in advance.

Azi

SolidworksParts And Features