I'll need to take the dizzy back out again for that grrr hahahah but i reckon that should sort it hopefully, pings a tiny bit as it is atm too

Got it idling smooth at 12 degrees, slight pinging/tapping still present. 

Drives bloody well now, but I'm back to the problem of the revs dropping right down when rolling to a stop ugggh

Its like the motor gets overloaded and almost dies, then idles up to speed again. Thats the only rough way i can sum it up?!? 

when u say "running at 12" I'm sure u mean base timing right? with vac advance unplugged and blocked?

if the 30 degrees u require for smooth idle is really base timing, then it sounds like either a lean idle mixture, or a compression ratio issue (missmatching parts, pistons and head to be specific).

An overly lean idle actually runs better with significant advance.

don't focus too much on this as ur issue, I'm just trying to make sure u have all the info.

Now onto the slowing down revs dropping,.  if u can't get it to run properly when u slow down with base timing at 12 degrees, but u can at 20-30 degrees, consider that this may be indicative of a lean idle condition. why? at idle, if the mixture is leaner than about 13:1 (at a guess) the combustion timing is greatly affected by spark timing, because everything is moving slower. so increasing timing can make a lean condition rough idle seemingly go away, but it will lead to detonation when driving. I'm really not sure how u are able to test this without a wideband o2 sensor but i think u have a car that is worth the investment in the test. Find a mechanic or someone with the ability to give a decent fuel mixture ratio reading. Banjo showed me a spark plug with a glass backing on it that allows u to visually check the mixture. The product is called colortune. takes all guesswork out of it.

uve come along way now, remember how it was lumpy and rough idle in the beginning, and now u pretty much have one last kink to iron out.

also i think ive gathered, that u have to remove ur dizzy to go between 10 and 20 degrees advance. perhaps ur unable to get the sweet spot in the middle. i don't know how but I'm sure its possible that this couod be part of ur issue.

Put it closer to 8deg at idle with the vacuum line unplugged and blocked and see how it goes. that's the stock value.  I never had any success running uber advanced timing on stock K motors, or any old two valve engines. They just have an old  combustion chamber design that cant handle advanced timing. 

I cranked the timing on my old Suzuki g13a engine thinking i was a backyard tuning god and when i was driving around on the road it "felt faster", i then took it to the beach and the engine really didnt perform well under high load. I backed the timing off on the beach back to stock and it felt "slower" but under load it performed much much better. It wasnt audibly pinging but it was definately worse with the advanced timing. 

You have to remomber that what you are trying to achieve is maximum toruque out of the engine. It is very possible, and ive seen it in my suzuki engine that you can lose torque from advanced timing without getting to the point of detonation.