James,
The HP-B Plus is a fantastic airbrush but its not so good when using model paints.
I also could spray fine lines with mine but the big problem was getting it to do so reliably which was my only complaint about it. Most model paints don't have the pigments ground up fine enough to pass through the tiny spray nozzle without the airbrush clogging up after only a few minutes.
I tried thinning my paints much more than usual in an attempt to get the HP-B Plus to spray like I had hoped it would when I first bought it but that only resulted in spidering or paint just being too thin to be that visible on the model which is useless.
After giving up on my HP-B Plus I tried one of the other new airbrushes I purchased which was the Iwata Revolution BR, the BR is a low cost d/a gravity feed airbrush that I bought for base coating my models and airbrushing backdrops. As an experiment I tried to see how fine a line I could get the BR to spray and I was amazed at how easily it was to paint ultra small details with it...the key to doing this is simply thinning the paint a little more than usual and lowering the P.S.I. down to about 10.
The painting experiments went so well I decided to paint the next model using the BR and it was a huge success and have been using the BR for the past eight years without a problem.
Below is my Tamiya Me 262A-2a that has a scribble camouflage scheme on it and was painted with the BR, could I have done this using my HP-B Plus? Yes, but it sure would have been a lot more work.

Again, your Me 262 turned out great (as well as the Fw 190)!
Matrixone