Cory, you have a good question and I'll need to check my references on what the R1 field mod was for. D-1's were originally supposed to be long range reconnaissance aircraft but only a few 'real' D-1's were made. After that, teh designation was given to any fighter with extended range and D-0's started showing up in loss reports as D-1's. These longer range a/c had provisions made for drop tanks under the wings and an external oil tank carried on the fuselage aft of the wing trailing edge. I don't see evidence of these in the photos. Some D models carried the bomb racks so it's possible yours had it. (Source: Vasco)
Just took a look Terry. As it turns out, once the cockpit sides are on you can't even see them! One even fell out without me noticing, as I found it on the floor some time later.
Got some Lichtblau on, actually had to sand some off and respray as a bunch of crap got underneath! Will be doing one of the top colours today. Kind of got carried away with construction!