Trying to make a surfcace I can thicken or shell

Hi,

Surfacing in SolidWorks is really great, however I am trying to make a simple computer mouse type shape, and shell or thicken it.

The file can be downloaded here:- Dropbox - Mouse Cover.SLDPRT

I am trying to make the basic shape from just two surfaces, however I am experiencing a problem knitting the ends. I am sure it might be a very simple fix?

I really need to be able to thicken the body to 1.6mm and either shell or thicken. I would also like to be able to adjust the shape moderately, as I will 3d print the shape, and test it ergonomically.

Im not super confident with surfacing, but once I have got this right, I am hoping that I wont have to edit it too much!

Can anybody suggest solution(s) ?

Kind regards,

JB

SolidworksSurfacing