I cant speak for authenticity, but pecatonica are great to deal with. Im very impressed with their help on the phone, to get help dont both emailing/faxing call them and talk to them.I built a half stock hawken as a first project (im currently on my third) and wish i had taken more time finnishing. I would also opt if its a percussion, for the lock plate without the cut out in it (the cut out to accomodate the patent breach)cos what they cut out wont fit the breach properly, YOU will have to fit it together to achieve a snug fit. With regards to the patent breach dont do what i did and ask the to fit it, sure they did a good job, but i didnt. I left the plug as it came and would have been better smoothing out the flash channel/hole in the breach i get some missfires. You live a learn.
Regards Dobson