I've copied here my reply to your post in introductions.
That's a Delta 40-540 and if the top Quickset blade clamp is complete and works as it should, then it's a great machine, built like a tank, will just sit on a bench, purring away all day long and not move, I've even had it sat on a workmate portable bench doing demonstrations at craft fairs. I've been using its brother the 2 speed 40-560 type2 (which I bought brand new) since 1995 and it's still going strong. I also have 2 540's and another 560, (they are identical machines except for the electrics, 2 speed v's variable speed,) which I've picked up over the years. I agree, parts are like hens teeth, especially the top clamp, (that's why I'm always on the lookout for cheap machines as spares, but so far I never had to rob one). So I would say go have a look at it, try it out and if it cuts wood buy it, (I would snatch it up).