Help with creating a parametric factory asset

[nstalker]

Hello,

I created this asset and shared it in the factory warehouse.

http://factorywarehouse.autodesk.com/Home#/Assets/Details?assetId=9e5ff301-795e-4662-990b-d08ae0b789...

It's a small frame on casters that I can change the overall length and width by editing parameters.  It works well for what I need it to do.

My next step is to create a Creform frame on top of it that expands with the frame as I edit the Length and Width parameters.  It seemed to be working up to a point.  I had a skeleton on it and it grew with the model.  But then as I added detail and edited the Length and Width parameters the detail started moving out into space and being disconnected from the frame.

I thought maybe it was because the frame was not centered on the origin.  So I did a move body and moved the frame to be centered and then started rebuilding the Creform frame on top using the Length and Width parameters to guarantee that it changed proportionate to the frame.  However it still ended up jumping all over the place.

Is there any way to update the origin of this frame that I have already created?  I could just start from scratch again but I was hoping there might be some tips and tricks that I was not aware of to help make this work before going back to the drawing board.