We have used Sugru and Lego (because we can)
Step 1: Kneed the Sugru
Split the first lump into two, you will need half each for the front and back sights
Step 2: Front Sight
Once we have a nice bed we place a 2x3 tile of Lego on top, careful to centre it with the length of the barrel
Step 3: Rear Sight
This time we place a 2x4 tile into the bed of Sugru.
Step 4: Making the Front Sight
We put the tiny dot on the dimpled tile.
Then we mould some Sugru round the dimple.
And create a point.
As you can see we got the first try wrong by 90 degrees.
As they say, "if at first..."
Step 5: Make the Rear Sight
Both of these sights are removable if you want to use the tactical rail leaving just the new mounts.