Thankyou all for such awesome responses, I've only been on the site 24 hours and love it already !
Minibuuls; yep the general consensus seems to be a mix of working-dogs, including a lot of kelpie.
Crazydog; now that you mention it, her 'mane' / body-type does seem to suggest some collie in there... as does her long nose... by 'cattle-dog' are you referring to blue and red heelers ?
Kalacreek; thanks for the kind words, I'm new to 'dog-forums', what does 'GSD' mean ?
Jjames; very kind, aye she is a great dog, forgive my ignorance but what do "GSD" and "ACD" stand for ?
Chipps; yep all pics taken under different conditions and with pretty crappy cameras, she is definitely of the 'black&tan' variety, es pecially after a goof brush. I'm with you on the 'bit of German Shephard'. Sounds silly, but this is based on watching her run around in a park with another shephard; very similar styles of movement.
Puggerup; as she ages (might be about 8 or 9 years old by now, precise age unknown), she looks more like a blue-heeler (in the face) every day... not sure if this is just a bi-product of 'growing old' !
Irracnna; yep, apart from the colouration, Kasay (a beautiful looking dog !) looks almost identical to my dog Luka. The facial features (eyes, snout etc) are very close in shape, and even the 'contemplative expression' is exactly the same. Funny how these things stand out.
SO based on the awesome input of all of you guys, I am deducing that Luka is about half Kelpie, and the other half made up of possibly 1/4 collie, with a bit of heeler and German shephard in the mix there somewhere... or something along those lines !
Thanks so much again for your time / suggestions !