ID these cylinders please

[Tommo]

I've found 2 front cylinders among my stuff and presume they are front cylinders for a WR racer.
They have 16581-52 stamped on the base flange and have angled valves.
One is in excellent condition with standard, 2.750, bore and the other one has no valve guides, is in very average condition and has a bore size of 2.786
Both have broken fins with the good cylinder only having one broken fin while the other one has nine.
Could someone please tell me what these cylinders fit.

[Rubone]

Tommo,
Those are standard K model cylinders. All K models have angled valves. From '54 up for KH and KHK long stroke models the suffix changed to -54.
Oh, and those are both rears.

[Tommo]

Robbie,
That'll teach me to look closer won't it.
Thanks for the ID.
Nobody that I'm aware of has a K series in NZ so it'll be back into storeroom for a few more years