First I must admit that I never used fibronectin antibody for my experiments. Since my specialty area is MMPs and tissue remodeling I have an interest on fibronectin. Since you are planning to try the antibody with mouse tissue in IHC, my advice will be to go with primary antibodies generated using a rabbit host.
I am sharing information of one such anti rabbit antibody validated against mouse tissue in IHC and a protocol of IHC in the attached file.
I most often take help of biocompare.com to search for antibodies for customized use. It searches for an array of different antibodies depending upon your need. Most of the time any direct search may not come up with the info you really need.
Just to let you know that biossusa.com provides free antibodies to test. I would recommend you to ask for a free sample and try with your tissue of interest. If it works then go and order for actual commercial size.
Thank you for the suggestion. I will look into all the options that everyone is providing! I will let everyone know what transpires, so the word can be spread. Thanks again for everyone's time, energy and commitment to research!