Disco 2 Missing bolt?? Help

Hi

Sorry what is a very "newbie" question but I'm paranoid about the unknown on my disco as the previous owner didn't exactly treat it well!

Looking underneath today I'm worried that a bolt/plug is missing.-see image. Is it?? And if so what is it?!
Please help or put my mind at rest

Thanks

timing pin hole ,there is a plug for it but wont hurt as is

Phew. Thank you!! Nothing like a bit of blind panic to get the heart going. I had visions of litres of fluid having poured out and metal grinding away!! Time for a beer I think