I've just done some checking...I'm not absolutely sure, but it looks like the G-codes that I've attached are the very same ones used for machining the blocks on the picture. The machine used is capable of 7500 RPM on spindle and F20 or F40 feedrates are no problem for larger endmills. For a 0.75" endmill a feedrate of less than F3 was used, though machinist managed to make one O-ring groove with F10 feedrate and 6000RPM without breaking the tool.
The program looks long, but it has to be...there are a lot of passes needed for a 0'75" flat endmill. It has no extension, but it does not need one.
It looks like there is no need for too many modifications after all, especially if the machine Mythe has got access to has the same or similar controller as HAAS VF-3.
If you look at the beginning of the program, under comments, there are tools and stock specifications, so everything needed for machining is there...the origin point is one of the upper corners of the stock and axis orientation is not hard to be understood from the toolpath provided.
This project was done by RalphW and me a while ago and I've posted pictures and details in the "Post pictures of your homebuilt blocks here!" Sticky, but they are gone now...
It is probably hard to believe, but I did not see the DangerDan RBX before making this design with changeable inserts.
The blocks are in our machines now and perform OK...I get 42.5C CPU core temperature with 1.75Vcore and 2.28Ghz on XP2400+ and water temperature of 28C on ABIT NF7-S.