Every now and then we do see a new question here!
I don't have any solid information, but here are my thoughts:
There is one pilot that I know of who flew fixed wing in the Delta and then got a helicopter licence. I imagine that he can't have had too many helicopter hours under his belt when he started flying them here. But this was many years ago so is not necessarily a good measure of the current situation.
As far as I know, the helicopter guys haven't had the same issues as the fixed wing pilots have had with immigration and permits. They are still employing recent graduates from overseas. However, you want to go the other way which is more restrictive and therefore more difficult.
A CV with that many hours will look very good to the department of labour and home affairs. They won't fully understand the difference between fixed/ rotary wing. Many pilots here have boosted their hours with simulator time, gliding, gyrocopter... for the purposes of showing more experience for the work permit application. So that should not be a problem.
CAAB have had issues with people holding both pilot and engineer licences. I have no idea what they will say about two categories of pilot licence. As I said before, it has been done in the past, but many years ago and before the new and improved(?!) CAAB. There is a chance that you could run into a problem when applying for a licence validation whereby CAAB tell you that you need 200 hours for a CPL therefore you cannot hold a licence. While it's not specifically written in the rules, the authority has been know to read between the rules and stick with one person's interpretation many times before.
The problem that I definitely see is with insurance. I checked a couple of policies in the office just now and they make specific mention of "fixed wing time". The policies I checked are fairly lenient, but do require far more fixed wing time than you currently have. If you came to Maun with a great attitude and a personality that one of the companies really loved, then maybe they would try to speak to their insurance company, but that is a risk and there's no guarantee that insurance will budge. I am afraid that most people would simply put you into the 'too hard basket'.
Good luck!