Hi Colin. The serial is 173340, branded 'LaFleur' 'Imported by Boosey & Hawkes FOREIGN.' The scribing is pretty crude. I love it. Have Link Tone Edge m/p on it.
If you're going down that route, be aware that putting it right could cost a lot more on top of the purchase price.
Unless you have the option of someone experienced/knowledgable checking it out it's probably better to walk away. You may miss a bargain, but you'll definitely avoid a lemon.
You're right of course, that's me getting over-enthusiasitc over serial no. lists, it's 70's ish. It's holding together well for its age, not a sax for people with delicate hands.