But, for future reference, here's how to make your own inserts.
You can buy sheets of insert plastic in various colors from Brownell's, or you can use a solvent-proof plastic to make your own.
Cheap screwdriver handles make great inserts.
You cut a piece of plastic and file to fit.
Use a Dremel bit to put a slight oval shaped cavity in the underside. This allows the epoxy glue to form a "lock" so the insert can't come out easily.
If the sight doesn't have two small holes in the bottom of the sight dovetail, use a tiny drill to drill two shallow holes. In conjunction with the shallow cavity in the insert, this forms a strong lock to retain the insert so it won't loosen or slide out if struck.
Another even easier method is to cast an insert into the dovetail using epoxy glue and model airplane paint.
Here's how:
Older S&W revolvers had two tiny holes drilled in the bottom of the sight dovetail.
If your sight doesn't have the holes, buy a small drill that's about half as wide as the sight blade.
Use the drill to carefully drill two shallow holes in the bottom of the dovetail. These holes were used by S&W and form "locks" for the insert to lock into. This makes a much stronger insert that won't loosen or come out.
Make sure to use a center punch to mark the holes so the drill won't drift off.
Use a solvent like Acetone or lacquer thinner to degrease the sight.
Make up two "dams" from small, flat pieces of metal or thick plastic.
Apply a coat of wax to the faces of the dams, then clamp them to the sides of the sight blade with a small pair of Vise-Grips to form a mold around the dovetail.
The wax prevents the epoxy from sticking to the dams. You can use Johnson's Paste wax or shoe polish wax.
Mix up some 1 to 2 hour type epoxy glue. The longer cure time gives more working time and allows the epoxy to level in the dovetail. Don't use 5 minute epoxy, it sets up way to fast.
After mixing the glue, put a SMALL drop of Testor's solvent-base model paint in the glue and mix it thoroughly.
You need only a very small amount, and the less you use the stronger the insert will be. If you use too much the insert will be weak and crumbly.
Experiment to find the right mix. Use just enough to color the glue properly.
Use a toothpick or needle to pack the epoxy mix into the holes you drilled in the dovetail, then use a small screwdriver or toothpick to put a drop of the epoxy-paint mix in the dovetail.
You want exactly enough to fill the cut to the top of the sight, level with it but no higher.
Brace the sight, (or the whole gun if it's on the barrel) so the face of the sight is level.
This will allow the epoxy to settle level and not run out.
After the leftover epoxy is like a hard rubber, remove the mold and use a brass or plastic "knife" to clean up any excess epoxy.
Allow to fully cure for 24 hours in a warm place, and you're good to go.
This home method works just as well as the commercial sets, and is considerably cheaper.
It's not really all that hard to do this with a little practice, and you can save some money.
Here's something I did to both my S&W Model 66 revolvers.
I made a black insert from a screwdriver handle and installed it, using the two holes and a cavity on the underside of the insert to form a strong lock.
Then I used a flex shaft and bits to grind a very shallow, oval-shaped hole on the insert. I filled the shallow hole with gloss white paint.
When viewed through the sights, the oval-shaped hole appears to be a white dot:
and don't mind attempting the front sight replacement if they're still available. 
