Hello Dave and welcome to the forum!
I can back up what Chris said with these pages from The Atlas Modeler (an online magazine that Atlas published a while ago, but has since been abandoned). The photos show how one handrail station was removed when GM extended the conductor side of the cab.









I bought one of the “revised” Walthers GP30s not too long ago from Toy Train Heaven when they had them listed in their mid-week Cloud Nine sale. They still have couple in stock, so keep an eye on their site if you’re looking for another at a good price. Just be sure you’re signed up to receive emails from them or you won’t get the notice the day the sale is running.

Mark

Thanks for the info! Quite informative.

Based on your responses, coupled with the extra parts included with the locomotive and the included parts diagrams having a few A and B options, it looks like I didn't ask the proper question.

The diagram does have A and B references for the two phases, but these parts (windows, window awnings/visors, a gray roof, walkway plank, etc.,) appear to have nothing to do with what you've described as Phase 1 and Phase 2. There appears to be no direct connection to the Phase references in the diagram and the extra supplied parts.

It doesn't help that the supplied diagram is very small and hard to decipher, even with my glasses. It looks like some of the A and B areas are made up of the same components?!?!?

So..... are these additional parts that came with the GP30 related to any cosmetic changes The Reading may applied to these units during their first two years or so of operation, before they renumbered them in the 3600s? If not, do you have any idea what they are for?

Daved and Confused

Dave...I'm assuming your 30 is a decorated model for the RDG...correct?
If so,you should find three gray colored templates.The gray roof you refer to is the template for drilling holes to mount the various roof details.I can't recall if the fire cracker was all ready mounted on my RDG units or not,that might be the only thing you might have to mount.

The oddly shaped piece is the template for the pilots for adding the pilot steps.The smaller template fits into the side windows to drill the holes to mount the wind deflectors.

The yellow all weather windows,sun shades are not used at all for the RDG unit.The green roof top ac unit and black snow plow are not used on the RDG unit either,put them in your spare detail parts container.

Walkway plank? If your referring to the drop steps they get mounted to the top center of each pilot.

Thanks Chris. Yes, it's decorated, and looks extremely close to some pics someone lent me of a few in the 5500 series. From the various angles (other than the underside, which I have no pics for) I don't see anything on the pics that is not on the engine.

'Walkway plank' was referring to the dropdown plate that allows crewmen to walk between the locomotives. I don't know it's technical or industry-given moniker. The P2K unit has these at both ends, but it looked like there's a single extra one in there that's bigger than what's assembled. When I just looked at it a bit closer, it must be the green rooftop AC unit you are referring to. Doh!

Looks like I will not be needing any of the extras or the templates, and will take your suggestion to put these in a parts bag.

Now, I just have to redo one of the two couplers that required assembly, as it wasn't returning to its center position when gently moved it off to the side, while its brother was re-centering just fine.