Chance to buy a rare very
early OHV Norton cylinder head dating from October 1923 (stamped 23/10). This head has had valve seat inserts fitted at some stage in its long life, and has regrettably sufferd a fair amount of fin damage which will need to be repaired, but the head (including the threads on both inlet and exhaust ports) is basically in sound condition. On Ebay motors, item 260773524448. See this blog entry
for the difference between early- and later M18 heads.