I've come across a similar thread in the General Discussion forum and have tried posting however the thread wasn't getting any attention

The car's an NA6, imported from Japan. I'm the second owner. There is a really bad fuel smell that is emanating from the boot and since there were holes in the rear parcel shelf left from a previous roll bar/cage, the smell goes into the cabin as well. I had Jason at Top Tune take a look at it, but without the either of us knowing where -exactly- the problem lies it will cost me an arm and a leg to get it fixed (time cost, quoting Jason)

I'll give as much information as I can from my own inspection:
1. The and the fuel filler and the fuel hose/line (running into the rubber thing behind the metal panel) doesn't seem to be standard.
2. I've checked the clamps on both the metal and rubber sections of the hose/line, they seem fine. So does the hose/line (from visual examination anyway)
3. When I press into the rubber panel thing, the fuel smell immediately comes out. I don't know if this is normal, I'm an absolute newbie MX5 owner... it seems kind of strange though.
So, what should I replace?
What else should I be looking at for symptoms to isolate the problem?
Where do you think the problem is? (I'm hoping it's only the line or filter or what not, and not behind that rubber panel thing where the tank is)
Your help is much appreciated!