Reading this decision, I would say you're likely to run into issues with the FCC if they were to find out about it:<p><a href="http://www.fcc.gov/eb/Orders/2008/DA-08-167A1.html" rel="nofollow">http://www.fcc.gov/eb/Orders/2008/DA-08-167A1.html</a><p>Relevant quote:<p><i>If the radio frequency equipment is modified by any party other than the grantee and that party is not working under the authorization of the grantee pursuant to Sec. 2.929(b), the party performing the modification is responsible for compliance of the product with the applicable administrative and technical provisions in this chapter.</i><p>In other words, if it's a certified device (has an FCC ID number on the label), you would need to obtain a new certification (new FCC ID) after making your modifications.  Doing so would probably eat whatever profits you stand to make (and then some).