will most likely be rust in the bores which could damage the block
see if it turns over by hand first, big spanner on the crank pulley or take the starter off and move the flywheel teeth round with a prybar.
i wouldn't bother going to all the trouble of draining the tank, there isn't a drain underneath it anyway so syphoning would be the only option unless you take it off.
just take a gallon can of fresh fuel and a length of 8mm fuel pipe. connect it straight to the fuel pump inlet, that will be bets for getting it running and won't have to pump the fuel so far
i've even known folks put the can inside the car when they want to give it a quick run around
not on the road though you understand
take the spark plugs out if you can and give them a clean up, be careful though as they can sieze into the alloy heads. if they feel they are going to break leave them in and wait until you strip the engine
some thin oil down the spark plug holes won't hurt too. crank it over a few times with the oil in the bores, it will help get some compression back in
is tempting to get it running though, i couldn't resist doing the same to mine and it had been stood for about 9 years