You're welcome Daz. like I say, get a decent camera and load a good photo/editing programme on your PC.
It's always difficult to judge what's in a dog just by looking at it imo. I can't remember the details but some years back, a century or so, some guy introduced bull terrier into the greyhounds make up to spice things up a little. And that apparently is where the brindle comes from, so technically you do have some bull in your dog
A strong wide chest could give some indication of bull in the ancestry. This bitch is grey/whippet/collie although I suspect the whippet was a hardblood t