Hi Lachie, welcome to Outdoorking.

Here is the Illustrated Parts List for your engine:
http://bsintek.basco.com/BriggsDocumentDisplay/Z6nmsFVJ1DajI.pdf

Here is the Operator's Manual:
http://bsintek.basco.com/BriggsDocumentDisplay/msowGK-K_ny7tH217FzoPu.pdf

The engine was made on 23 July 1982, so it will be one of the first Briggs engines to be fitted with Magnetron electronic ignition (no breaker points or condenser).

There are rules for which way you can tip a 4 stroke lawnmower. If you tip a Briggs engine toward the valve chest, the valve chest will fill with oil and it will go through the breather pipe into the carburetor when you start it. Always tip it in the other direction so that the cylinder is upward.

So far as getting your engine running is concerned, the first thing to suspect is that when you ran it out of fuel, it sucked up a bunch of garbage from the bottom of the fuel tank and blocked the filter-screen on the fuel pickup tube on the bottom of the carburetor. While you are fixing that, it makes sense to strip the carburetor and clean it properly. It will probably need a new diaphragm after all those years. The 92908 is very unusual in that it has a Pulsa-Jet carburetor with an automatic choke, and unlike other older Briggs carburetors, this means the carburetor has to be serviced, and in particular re-attached to the fuel tank, carefully with the instructions from the workshop manual open in front of you. If you do not preload the diaphragm correctly when re-attaching the carburetor to the fuel tank, the choke will not work. So, you need to get a copy of the Briggs and Stratton Service and Repair Instructions 1984, though you can get by with a copy of the Single Cylinder L Head tech manual.

The stripped bolts are your main problem, and if you can't solve it, there is little point in worrying about your carburetion problems and the oil sloshing around in your combustion chamber. There are two ways to deal with a stripped bolt. The cheaper and easier way is to tap the thread to the next larger size. The more expensive way, which is mandatory for collectors' piece projects, is to fit a helicoil so each repaired thread ends up the original size.

Frankly, unless you are something of a mechanical hobbyist, you have a fairly difficult job in front of you repairing the stripped bolts, and it isn't really worth doing unless you aspire to becoming a mechanical hobbyist.