Yeah I agree the cam gears look worn. As owner of the "pointy ones” in the other post, let me try to explain why yours look worn.
1) Pointy teeth do not necessarily meant sharp teeth. My pointy teeth were not sharp and still had flat tops.
2) As a chain stretches it places stress unevenly on the gear teeth and deforms the tooth profile. You will end up with a hook shape as the valley of the tooth becomes elongated. This is pretty evident in the first picture you posted. If you look at my cam you will see a more uniform shape and wear profile in the teeth valley.
3) You can measure chain stretch with a tool or with less accuracy with a ruler; however you need to know the standard length for a number of links for a new chain. (I don't know what this is in the M42) If there is any meaningful stretch it doesn't matter what your teeth look like you will be toast soon.
Ignoring general wear which uniformly loosens things up, hooked teeth come from chain stretch which comes from stress. I don't know if there is enough mass in the head to create much of a load, but it’s pretty easy to understand how hard acceleration is going to unevenly load the chain versus smooth acceleration. So style of use certainly affects the degree of chain stretch and thus the wear on the gears.
On my car timing chain and gear replacement is high on the priority list mostly because of oil ooze from the lower timing case sufficient to cause overnight spotting, and evident, if not excessive, wear.
The link I posted above has the link to the cam gear at pelican parts in the last post
Brendan Purcell's page has the best DIY on changing the timing gear that I have found:
http://www.esatclear.ie/~bpurcell/318istimingchain.html
