Hello,
3D parts do not have the strength of molded parts. They are only to show and tell, some form and fit - not much function. So unless you mold you will not know for sure. It is best to talk to a material supplier and they will give you suggestions of fillers that you can use to get the strength. As I see it, you are 'almost' there and so should not be too difficult.
Let us know.
Suhas