no problems peter at all, loads of metal.
tips
you want 2.5mm wide seats. press the exhaust valve guides out, have 6mm taken off the end and shaped to the same finish. use various sizes of washer to indicate a round port and looking back up at your face using a torch - looking for chinks of light and taking the high points out.
take the port out to 100% the vales size except the last 10mm above the seat which comes in about 2mm. port at every angle and from both ends. press the guides in and then have the seats "3 angle cut". seat width 2.5mm. watch the key lock on the drill from graunching into the valve seats - the ehad you can clean up but the seats are precious!
felt tip the valve's seat. kiss it in and then any felt tip left use a a grinderette with P60 on it whilst spinning the valve in the drill, remove felt tip and assosiated metal. finish by hand.
you have a huge parcel on the way today and another by the end of the week.
TF: 4 c/b bearings, HG, top end cam, flywheel puller. cam grinder made a mistake and supplied a torque cam so another customer's cam after your's is going to be your's. expect 10 days from today to be sent....
regards
Taffy