That is a 59-67 engine lid, there are a few details that are different on the 59-67 lids, mostly to do with the lock mechanism, otherwise basicly the same design.
The 58 engine lid is a one-year-only lid, same design as 55-57 but with no brake light, a flat engine lid with no 'eye brow' over the license plate.
Unless you have any special SA specs on your buses...

but anyway, looks to be a good condition lid, perfect for someones resto!

The engine lids you have on your Fleetlines looks like the '58 OYO lids.