[700rpm]

If it ran fine years ago there is no reason to check the timing. Sitting cars will not just fall out of timing. I suspect dist. body if you have determined that spark is getting through the dissy and two plugs but not to two others. Replace that bidy with a new one. I don’t usually suggest throwing parts at a problem, but in this case that’s where I’d start with this. Clean and gap your plugs while you’re at it.