First, I think it's nice of you to track down a part for your friend in Africa.
There are several widths of the front sight and it would help if you knew if it was a .243" wide or .278" wide sight before ordering.
You might also look up "Gunsmith" in your local phone book. Most of them should be able to order the correct parts for you.
You can also check with:
Gun Parts Corp -
http://www.e-gunparts.com/dept.asp
You should be able to search on Model 27 Sight Blade and get some results.
Don't forget to order a front sight pin too! The web page has "exploded' diagrams of the revolvers to aid you.
A quick search shows a sight assembly with the following info;
Smith & Wesson 27-3
Item No. 322030A
Front Sight Assembly, .243
Retail Price: $44.40
Smith & Wesson
Item No. 322780A
Front Sight Pin
Retail Price: $1.25
I'm not sure just what the assembly is unless it's the ramp and blade.
You can call them to ensure you are buying the correct part, the folks there are very helpful.
The other possibility is to contact
Smith & Wesson and inquire about the correct S&W part number(s) & width and if they can provide a replacement part. If not, they may have other suppliers to direct you to.
http://smith-wesson.com/
Brownell's (
http://www.brownells.com) also lists;
Sight Ramp, Front,
.278", Black Serrated
w/Red Ramp Insert $21.86 #940-000-820
Sight Pin, Front $1.58 #940-053-720
Good luck on your search!