Your best bet would be to
sell him as a whole, two halves, or four quarters and have him processed at a
local custom processor. This will get around many of the problems with licensing and health department rules since you will legally be selling him to one or more people as a live animal and just delivering him to a processor for the customers. The safest thing is to have the customers deal with the processor directly for their cutting instructions and pay the processing fee themselves. We do this fairly often for co-ops besides our standard cut beef sales. I would charge at least $4/pound based on the hanging weight (this is assuming they pay processing and pick up). We are currently charging $4.50/pound for our beef animals (we do include processing because we have the needed licenses to resell meat and us a state inspected processor) but will be going up soon because
cattle prices are skyrocketing.
For a
dairy breed you will probably have a hanging weight of about 50% maybe 55% of live weight. You can then expect about 50% of hanging weight in retail cuts. I haven't eaten Guernsey, but I love Jersey meat. It has a distinctive sweet taste. The only problem is most of the cuts are much smaller than in beef breeds. Personal single serving round steaks for example. These were from 700 pound steers though.
Check around for local custom, state inspected, or even small USDA processors.