[swedishandgerman]

As well, check the vacuum can as follows:

Apply some vacuum - you could suck it with your mouth - and you should have some resistance.
If there is no resistance, the vacuum can has perforated; you will be able to suck and suck and suck!
If it has perforated so badly, it is possible that there is zero resistance allowing the points base to flop about badly causing the timing to go about the place.

I've frequently seen this on aircooled VW which has a similar distributor.

Also whilst sucking with the distributor cap removed, you should see movement in the points base.

My advice on a 099 distributor, by the way, is to leave the thing disconnected. It is a vacuum retard system and gives zero improvement to performance and efficiency. It's just there to retard the timing when there is massive vacuum in the chamber like quick throttle close (changing gear) and going down hill; the retard helps burn the gases in the chamber so it doesn't go straight out the exhaust. However, even if you are leaving this disconnected, the vacuum can still needs to be in good shape otherwise it will flop about!