sirmick,
I was in a similar position. I wanted my PE (in mechanical/machine design) so that I could have the option of pursuing consulting work in the future, as well as for personal reasons. Working in manufacturing, however, made it difficult to come up with the required three recommendations from PE's familar with my work. In Missouri and perhaps elsewhere, your immediate supervisor is supposed to be a liscensed engineer as well.
My boss happened to be a liscensed Coast Guard engineer (liscensed to work on ship engines 20 yrs ago), and I scraped up 2 other PE's who agreed to provide recommendations.
I sent a letter to the Board explaining the "chicken or the egg" problem I was facing and basically told them that if they wanted to make any inroads into manufacturing engineering (which, as in your case, largely doesn't care about PE liscensing) they were going to have to make allowances when it came to recommendation requirements. They agreed to accept a third recommendation from a non-PE engineer and allowed me to test. I passed!
I understand the reason for the PE recommendation requirements as a character check on the applicant, but manufacturing industries just don't have the access at this time to PE's like someone working for a civil or structural engineering consulting firm does. Many times, the manufacturing engineer is far and away the most technically educated person in the plant. Unless he has the opportunity to work with outside engineers on a regular basis (as I did), it can be very difficult to get the recommendations. The upshot: provide the board with the best you can in terms of recommendations. If you can't get all PE's, get engineers in positions of importance. If they still don't want to let you test, try to speak to board memebers and explain your situation. Maybe even your state representative could help if the board is unresponsive.
If the states want to insure a minimum level of engineering competency in manufacturing (which IMHO is sorely needed), I think they will have to revise their existing recommendation requirements, at least until some critical mass is reached.
Good luck!