There are a few specialized parts in the field, but perhaps the first step should be to take a look at the field model building instructions to see if it were possible to build some or most of the models from parts you have on hand already. The field mat is a different story of course. However, you are in luck in that regard. I happen to have several lightly used mats on hand. If this option sounds plausible, I would ship a mat to you for the cost of shipping and rolled container. Let's PM details, etc.
Check with your regional partner first. Many of them are happy to promote FLL in whatever way they can.