I'm thinking of getting a double-sided cast iron griddle like this:

http://www.amazon.co.uk/Kitchen-Craf.../dp/B0001IWZ8G

but I've noticed that the non-ridged side has the unmachined cast
iron surface, whereas a machined surface is generally considered
better.

http://ask.metafilter.com/148245/Man...Cast-Iron-Pans

http://grannysvitalvittles.com/why-y...-iron-skillet/


Is this something that a machine shop in the UK could do easily &
perhaps cheaply? What exactly would I ask when phoning up --- "can
you just mill the cast surface off an iron griddle?" or something like
that?

Thanks.