Hi Jepps,
My father was the man behind the Microflight A300. He passed on a few years ago. I do have access to the software he had developed with Microsoft over the years. It will all depend on what version of the sim you have. Does it have any USB ports on it? Or does it have the serial ports? This will determine an approximate build time frame.
You have something in your possession that is rare to say the least. Less than 500 were produced, although with Pops gone, no one can say for sure as he kept all his records in a cryptic IBM format that only he could decipher.
If you have some pictures you could send, I can try and help you out with getting your Microflight A300 once again soaring above the (virtual) clouds