Haven't some of the Mini clubs their own registers that kind of have this, at least for genuine Coopers? (Please, I have no wish to start a flame war on what is or is not a genuine Cooper?)
That said.. would be good to have a reputable public repository for Mini's in Australia that shows their origin (as in where made), their original market of first ownership (Australia, UK, NZ, Italy, Japan, wherever), relevant original numbers, current engine number (appropriately censored if need be?), what it started life as to what it presents as now (e.g. an original Mk1 Cooper S that is still a matching numbers car OR an original Ccoper S that no longer is so OR perhaps an original 850 that now is a Cooper S replica/tribute/copy/whatever you want to call it?), current owner, details verified by (as in a known reputable source, e.g. Siebler, Russell, Pope, VMCi, etc). (as after all, the value of such a register would be far more if individual entries had some accepted expertise in verification rather than relying on self-validation?) etc.....
Would be a merde-load of work
. However would be a terrific resource if it were at all possible? 
Davo