That's correct, you have to paste the part between the HTML tags (the parameter=value lines and piece definitions). This should make the diagram appear on the Play-Test Applet's board. (In this case a bit squeezed, because your board is too wide for the page layout, but still bearable.)
The choice of piece images is controlled by the lines below the green header "Additional Pre-Game code (only needed with non-standard piece set)":
set mypieces assoc
P "wquickpawn.png" p "bquickpawn.png"
S "wsergeant.png" s "bsergeant.png"
...
Q "wqueen.png" q "bqueen.png"
AZ "wamazon.png" az "bamazon.png"
DW "wdragon.png" dw "bdragon.png"
K "wking.png" k "bking.png";
setsystem dir "/graphics.dir/alfaeriePNG35/";
setsystem pieces #mypieces;
The forelast line defines the directory from which they have to be taken; it uses the 35x35 alfaerie PNG set, because that is what the Diagram that you pasted used. (It just copied the directory name from the graphicsDir parameter of the ID.) If you want the 50x50 pieces you can just delete the 35 suffix.
The sergeant apparently occurs twice in the list; not sure GAME code would like that, so you might have to delete one of the lines.
BTW, this code for defining the piece set is really independent from the other provided code; it should work in combination with other GAME code for automating the preset as well.
I am not sure about the "missing and wrong ones". Beware that GAME code is only executed once you start using the preset for playing. So any method of defining piece images through GAME code will have the problem that the initial image one gets when loading (and editing) the preset will still use standard images and piece labels, and only when you press 'play' the Pre-Game code is executed, and you will get to see the pieces you asked for.
That's correct, you have to paste the part between the HTML tags (the parameter=value lines and piece definitions). This should make the diagram appear on the Play-Test Applet's board. (In this case a bit squeezed, because your board is too wide for the page layout, but still bearable.)
The choice of piece images is controlled by the lines below the green header "Additional Pre-Game code (only needed with non-standard piece set)":
The forelast line defines the directory from which they have to be taken; it uses the 35x35 alfaerie PNG set, because that is what the Diagram that you pasted used. (It just copied the directory name from the graphicsDir parameter of the ID.) If you want the 50x50 pieces you can just delete the 35 suffix.
The sergeant apparently occurs twice in the list; not sure GAME code would like that, so you might have to delete one of the lines.
BTW, this code for defining the piece set is really independent from the other provided code; it should work in combination with other GAME code for automating the preset as well.
I am not sure about the "missing and wrong ones". Beware that GAME code is only executed once you start using the preset for playing. So any method of defining piece images through GAME code will have the problem that the initial image one gets when loading (and editing) the preset will still use standard images and piece labels, and only when you press 'play' the Pre-Game code is executed, and you will get to see the pieces you asked for.