
I know many shows who get offers for mr and mrs goble sponsers £10 for BOB and £5 for BPIB! That is common, have never heard of anyone sponsering a group. Maybe thats just my area of shows! Sponsoring of rosettes is common for class or breeds and normally is space for this on the entry form! :)
Like already said contact the secretary who can put it forward to committee, but any committee who refuses must be stupid for not excepting money! :D
There is no problem in you sponsoring the classes you go in. YOu can always donate as anonoymous! (sp!) :)