Sorry folks.....but could not find any engine serial number.
I have however, just got my Blazer registered
Turns out that on exported Blazers, the engine number is supposed to be able to be found through the passesger side (originally driver's side) wheel well....but you need a fibre optic camera to get far enough into see where it should be. However, quite a few exported Blazer's do not have an engine number stamped on the engine block!
In my case (South Australia, Australia), this necessitated proving that no engine number was on the car, then being issued with a "Police Number", and having to have that stamped on the engine block.....very hard to do without removing the engine, as there is no room!
Anyway, all is now well and I can drive my Blazer
Thankyou everyone for your input!