Hi Mick,
If i had to critique your poster, I would say that you could have chosen a better typeface, maybe a sans-serif type, also the curved type don't work as much as it would if it was straight. I don't think the grey works as the background also, remember if this is a poster it has to deliver the information needed quick, without having to stop and figure out the writing. The other thing is that you put a copyright symbol with your name, so that your client cannot 'nick' it without paying, someone can easily remove that because you have it on a solid colour background.
I like the illustration, looks good!
Thats my 5 cent for your future poster
Take it easy