Well this should provide you with a good laugh! 
On leave this week looking after my daughter (school hols), so I thought I'd have a go at the Premier 160 to see what condition it was in. Not done as much on the mower as I wanted due to other commitments (read:daughter!), but anyway...
I'll ask questions as I go, hope you all don't mind (and do answer

)
I think it's a good example of 'don't judge a book by it's cover (nice Pace stickers).
Got the plug outlast week and peered inside, seemed OK. Plug is a rather worn Champion N-21 , covered in black soot- looks about normal actually.
Does the N-21 plug sound right, are they available and what would be the gap? (Small engine manual says: consult the dealer)
Cowl and starterIntending to get at the carby, first thing was to get the cowl and starter off. First thing I noticed: one missing bolt and two on one side sheared off- actually saw this last week. Not a good start, but anyway three bolts later and here's what I saw. Even by my newbie standards, it's an "Oh, dear" moment. Some queries will precede/follow each pic, please have a look and help me out if you can. Thanks!
Starter drum(?correct?)- I assume it's not meant to be in this condition, looks extremely worn to me- teeth (I assume?) gone and you can see where something's been rotating in contact with it on the top surface (starter base)?
- And what's the little sector of metal- is it a shield/shroud part from the starter unit itself (pics further down)?
Starter base from underneath - Again, contact from where the base has touched the drum?
- Contact likely caused, I assume, by collapsed shroud bolts?
- Should there be three 'prongs' (dogs?) extending, also is the broken off part likely the shroud around the outside between the prongs/dogs?
Flywheel - Basically every flywheel blades seems to be broken- again contact, no doubt, collapsed cowling?
- Contact again can be seen at top of drum(?)?
Cylinder outsideProbably least of my worries, but
I wonder where all the contamination came from, and whether the engine overheated (and was damaged) as a result.
Ignition and compression test Last thing was to test the spark: I pulled the plug and spun the engine, both by hand and by a rope around the pully. I guess I would have simulated a zip-start speed. Even moved the throttle cable, though I can't see any kill mechanism connected. No spark found, darn.

But it does seem to give compression, so that's help.
Next steps- Pull the carby
- Pull the exhaust
- 'ave a look inside
- Pull flywheel (get to test my new purchase )
- Look at ignition
- Examine/dismantle carby
ConclusionSo my first-off opinion is whilst it
may be fixable it's pretty well a write-off from the start. But no matter, that just makes it great to learn on, doesn't really matter what I do to it!

So I'll probably pull it apart and try and get bits working anyway. Some may even be salvageable. I suppose if the cylinder's good then the flywheel, magneto, carby etc can be replaced/repaired and it can work anyway, perhaps replace starter with something else.
Already a good learning experience!

Cheers,