BN24 is as good as it gets (n.b. there is more than one variant of BN24...)
Anti-clockwise rotation, 7-8.5 degrees of advance.
The "correct" advance spring set is 405396/S but as I recall the "Distributor Doctor" supplies a substitute 405508.
p.s. I just checked and yes, my DK4A with DHYH4A internals is on Mrs. Lopsided. Please consider that likewise, your unit may say BN24 on the outside, but there's no telling where the internal parts came from. If you suspect they are from a later unit you might want to check the lift & shape of the cam against a reference part, as this may affect how you should set the points. One clue is that you may find the advance angle stamped on the action plate. FWIW my hybrid unit (with home-made springs) has done 1500 miles since fitting and is running nicely - which suggests that being somewhere close is at least better than sheer neglect.
Anti-clockwise rotation, 7-8.5 degrees of advance.
The "correct" advance spring set is 405396/S but as I recall the "Distributor Doctor" supplies a substitute 405508.
p.s. I just checked and yes, my DK4A with DHYH4A internals is on Mrs. Lopsided. Please consider that likewise, your unit may say BN24 on the outside, but there's no telling where the internal parts came from. If you suspect they are from a later unit you might want to check the lift & shape of the cam against a reference part, as this may affect how you should set the points. One clue is that you may find the advance angle stamped on the action plate. FWIW my hybrid unit (with home-made springs) has done 1500 miles since fitting and is running nicely - which suggests that being somewhere close is at least better than sheer neglect.