These were built by Les Hayden in Montague Gardens, just North of Cape Town, RSA. I think 1998 (month unknown) would probably have been the year of its first manufacture.
The original Darts were first built in 1957 and to my eye, it's a testament to the brilliance of its designers that these cars are still so beautiful and such fun to drive even today, when car designs have moved on so much. I will say, though, that I think the Hayden Dart is much more professionally-executed and better finished than the 1957 originals.
Thanks for holding my lock on for so long, Carnut. Bit of a bad patch health-wise has kept me away from the computer for a while.