Hi @Anonymous,

Here is an article that describes the CONVTOSURFACE feature.

I suggest breaking the model into parts first. Perhaps do this by placing a grid as a reference for naming the pieces.

Then, wblock each part into it's own file.

Open the first one and in modelspace, run CONVTOSURFACE and select ALL. Then you should be able to export.

Then, bring it into Fusion 360. I brought it in with Design from File. If it is still unwieldy, please add a post and we can try to figure out another workflow. 

Please select the Accept as Solution button if my post solves your issue or answers your question.