In the United States, WW2 marked the high point of solid gold pen production. Pen output as a whole was sharply restricted, so manufacturers radically increased their production of deluxe models; higher wartime wages plus a general shortage of consumer goods made luxury items quite saleable, and there was more than enough gold available for military needs.
By far the most common war-era gold and gold-capped pens are Eversharp Skylines and Fifth Avenues. Sheaffers are a rather distant second. Gold-capped Parker 51s are not common, but the vast majority were made in this period.
Even minor dings in a solid gold pen greatly reduce its desirability. On the more common pens, such as the Skyline Command Performance, personalized engravings have a similar effect on value. This is not the case with earlier gold pens, however, which tend to attract buyers who are more collectors than consumers.