Identify lock please?

[Turtle]

 I am working on a friends flintlock longrifle and it has a lock I have never seen before. On the outside of the plate is stamped KINGSLAND xCo. WARRENTED. above the name is a R. It is a small well made lock with a roller and on the mainspring-which I haven't seen before.   It has nice engraving on the plate and cock. Any ideas? sorry no picture.
                                                              Thanks,Turtle

[Turtle]

   After more inspection and research into this lock, it came through my thick head that this gun is probably and original-not an old repo as I assumed. There is no makers name on it. it has a heavy(over 1" wide) barrel of 42 1/2 caliber with extremely deep(.030) and narrow grouves. It has a real nice curly maple full stock. I'll try to get pictures posted and maybe somebody can help me ID it. This is exciting.

[Turtle]

 I reposted this on the gun collecting page.

Here's a link.....
http://americanlongrifles.org/forum/index.php?topic=54037.0