Thanks guys. Started the scribing today and here are a few shots of the process I use.
As a guide for my lines, I use this clear Dymo tape which is fairly low tack:
After cutting a strip of the tape and removing the backing, I line up the scribe lines along one edge and burnish the tape once it's in position. On the spine, you can see the tool I use to scribe the lines.
Here's what the line looks like after the scribe is done. The rivet pattern was continued using a sewing needle but unfortunately I pushed too hard on the puttied part on the top of the fuselage and chipped the putty. This will have to be touched up.
To scribe the circular panels, I marked the center and attached a template. The circle was carefully traced with a sewing needle, lightly at first and then with increasing passes until the right depth is achieved.
Here's the finished area with a few repairs evident. The circle is scribed right on the puttied area and I took care to keep the cut shallow and mostly in the paint layers.
Next will be a layer of RLM 65 over all the surfaces and no doubt some further touch ups. Thanks again for looking in fellas.