[OXO cube]

i used munters guide also and everything was good 

except:-
be sure to use the absolute minimal amount of dye when mixing 
not only does it go a very very long way 
( be sure to wear the surgical type gloves )( looked like i had frost bite finger for a few days after lol )
but too much dye has a detrimental effect on the resulting tyre grip 

my 1st attempt was shore 30 ( 40 is better imo ) and due to using too much dye , the grip was rubbish 
looking at manufactured urethanes ( eg:- ortmann ) , they are slightly transparent 

just an fyi 
hope it helps 

kev

btw :- 
you prob have enough material there for about 400 - 500 tyres