Well, now thats more like the community we know and love!
Thanks to Krinkels and Alex I can sort this thing out, hopefully.
To anyone who is interested, the SWF file is what you publish and the FLA is the flash when you first make it. Krinkels told me something I didn't know - that you could convert the former into the latter, and Alex took the trouble to give me a link- which is great for me, since despite being here for years, I am not really very computer literate.
The link he gave me gives you the chance to buy a program to do it, or download a limited trial. The catch with the limited trial is that is doesn't convert any coding, so you get a file with a whole sequence of images that I will need to re-assemble, as Alex said.
However, subject to sorting out the dispute that lead to my stupid decision, Since I have a quiz template to drop images onto, it should be OK.
Conclusion:
1. If you get stuck, try and figure it out then ask on NG. Whats the worst that can happen? Being called names didn't kill me.
2. Agree terms and credit before starting a collaboration and negotiate any changes as you go along.
3. If you argue- stop and sleep on it. Things may seem different in the morning!
4. Try and help people a little as well as insult them. If the great Krinkels can spare a second, so can we all.