I've started browsing some of the antique shops I found here in Budapest. I found a red Parker 51 with silver cap. Then I found two Parker 51s in a different shop, both with gold filled cap, black color. I noticed both have different looking endings on both sides. I could guess they are from somewhat different times, right? Also found a red Parker, I don't know what type it is. It has 585 on the nib.