Ok so update if anyone is interested, I ended up cleaning the head myself which came up ok eventually, except I had to use the rocker assembly from my old head as the ones from this head had blocked oil passages. I got the head skimmed and checked the valves sealed.
Pulling my old head off was positively surprising, the cylinder walls looked great, there was no noticeable piston slap and once I cleaned off the old gasket material, the block surface seemed straight enough. Torquing the head down went smoothly, and after cleaning everything and putting it all back together it started right up. 👍cheers to all who helped along the way