To the best of knowledge, no one. I have spent a fourtune making my 556P (SBRed) look as like a 552 as I can. MFIAP.com has a bunch of look alike parts. There was also a guy on here that bought a 552 (minus receiver) and built it. Not sure how the final product turned out, I know he had difficult finding everything. Good luck and check out the SBR page photos.