Mark,

I posted this over on British militaria for you, I'll post here also.

You need to be persistent in your search and you may find this sight.

Here are some other places to post.

http://forums.gunboards.c...p?15-Martini-Henry-Forum

http://www.rimfirecentral...7ac27d012d84d&forumid=69

http://www.milsurps.com/forumdisplay.php?f=115

http://www.jouster.com/fo...7f91a58d630e6439049d7b12

http://www.assra.com/cgi-bin/yabb/YaBB.pl

http://www.gunsite.co.za/forums/

I would also go to the Martini Internet resource list http://www.martinihenry.com/links.htm and scroll down the the list to the sights and sights parts section and contact everyone listed there.

After you contact them, then contact every dealer listed and see if they might have the sight.

Good luck.