Quick follow up, got the battery on a charger and it wasn't that low, so figured it wasn't a charging issue.
Battery cables and grounds were good.
Two connectors under the seat had gotten wet a couple times and had some corrosion. Cleaned them up, put on a light coating of dielectric grease. While I was in there checked resistance to the starter button and it was way high. Cleaned it up with a points file (remember those?) and now .. not only does she start, but does soon the first push with no delay.