I remember seeing this game and wanting it, but we did not have a computer. Once I was finally able to play it at home, it was no longer sold/found in stores. It wasn't until a couple of more years that I was able to buy GP500 as a full-game release through a PC gaming magazine, and I was finally able to enjoy it.
By then there was Superbikes 2001 by EA that looked better but GP500 was special as not only it captured the (now long gone) 500cc machinery, it featured a few historied riders and a good calendar, and it had simple but dreamy gameplay. The modding community also greatly extended the life of this game through the Windows XP era but it has become impossible to run it with modern machinery and OS outside of a Virtual Machine.
This being on GOG would be absolutely fantastic. Melbourne House did a great job with this game and it was part of Micro Prose's rich history.