Missing Tappet Locknut

[mick-ne]

So I am putting a 1100 Slabby back on the road and decided to check the Tappets.

One exhaust valve tappet is missing  a locknut it was on before.

I have pulled the oil pan expecting to find it as the valve is right by the drain tube but nothing.

Nothing to be seen in the head any suggestions welcome as im stumped lol

Thanks

Mick

[TonyGee]

you'll have to go fishing with a magnet before the strip down