I do my best at the NINE GTA Special Vehicle Guides as I can, plus making Save Files and Starter Saves for these Games, plus re-confirming all Vehicles in IV (reading Scripts and obtaining them to see them in Save Editors to check if they're Special etc.), plus other real life annoyances and Projects which I have to complete.
I don't know why you want to re-make your own III Special Vehicle Guide, while mine on the Forums is actually fully finished fully up to date... Others still need some tweaks and repairings which I will complete in the coming months.
Like Craig said, if you want to share your findings, show it in the existing Guide, and then I will add them into the Guide if they're Special and true. Trust me, making your own Guide is not easy at all and it's a huge chore.