Jim, I think you have done fine. Good chipping, the Japanese paints from that period were sure prone to it. The decals were probably a little old and probably could have used a coat of liquid decal restorer. I know you might not have any of that yet, but I find it very useful, especially if you get kits off the net, or (like many of mine) from a thrift store. Trim as closely as possible to the design, then, as Andy suggested, apply over a coat of gloss. This will make them adhere to the surface much better. Alot of us use Future floor polish, it is a very tough acrylic useful for making canopies look like glass as well as a good first coat for decaling.
Over-all though, a great beginning!