I also have a number of Dowidat tools my Dad bought in the 70's. I remember thinking the brand name sounds like something a cricketer with a bad cold would yell out.
Those multi grips are the same as the set that came with my dad's 403B in 1961. As Russell mentioned they were a fairly comprehensive little kit...and the grips and spanners were forged but not plated... decent quality. I still have most tools...the tube plug spanner's soft metal 'rounded the flats' and became useless. The screwdriver had the metal shaft going right through the wooden handle and the blade had an excellent edge for locking front wheel hub nuts.
The contemporary Holden FB/ EK got nothing like the pug tool kit back then.