There were 3 Railroad Specials: the 50, 51 and 52:

• 50: All stainless steel
• 51: Stainless steel with a 10K GF bezel
• 52: All 10K GF case and bezel

All have a 505 movement but with a micro-adjuster on the regulator for more accurate time regulation. The 52 seems much rarer than the other two. The 51 is very similar to the Hamilton Clearview.

As you can see, over the years I've had many Rialroad Specials. Being relatively large at 37mm, they are very wearable despite being 45 years old. All have a screwdown back and date from mid 1960s.

Hamilton RR Special 50; Calibre 505; all stainless steel; 1965ish. Nice blued second hand on this one but it is not correct, it should be the normal red flash second hand.	Hamilton RR Special 50; Calibre 505; all stainless steel; 1965ish. Nice blued second hand on this one but it is not correct, it should be the normal red flash second hand.	Hamilton RR Special 50; Calibre 505; all stainless steel; 1965ish	Hamilton RR Special 50; Calibre 505; all stainless steel; 1965ish	Hamilton RR Special 50; Calibre 505; all stainless steel; 1965ish	Hamilton RR Special 50; Calibre 505; all stainless steel; 1965ish
Hamilton RR Special 51; Calibre 505; Stainless steel case with 10K GF bezel; 1965ish	Hamilton RR Special 51; Calibre 505; Stainless steel case with 10K GF bezel; 1965ish	Hamilton RR Special 52; Calibre 505; 10K GF case; 1965ish

Four RR Special 50s.	Two Special 51s (left), two Special 52s (middle) and one Clearview (right).	One of each: 50 (bottom left), 51 (top left) and 52 (right).	One of each: 50 (bottom left), 51 (top left) and 52 (right).	All three types with a Clearview on top.
All three types with a Clearview on top.	All three types plus a Clearview on the far right.	All three types plus a Clearview in the foreground.	All three types plus a Clearview in the foreground.