Question on spring ordering

[Chwderhed]

Ok, so I am looking at ordering new rear leaf springs for my truck. 1967 Mercury M100 4x2, with a 300 engine. I can't seem to find anything that corresponds to what I'm after. It seems like all the sites I look at don't list exactly what I'm looking for.... I am probably reading them wrong though.
What I see from the picture starting at the top is 1/5/1 with the top single leaf being added afterwards.
Can someone tell me from the picture of the rear springs just what I should be ordering? I believe that it should be the "5/1 1250 lbs." units from Eaton, and that the extra spring at the top was added afterwards.

[fordamericana]

M100 is an F100 made and sold in Canada No differences in the trucks, Canada got all concerned that the US was building vehicles in the US and selling in Canada that they weren't collecting taxes on, so to resolve that issue, Ford built and sold Mercury M series trucks in Canada and the Ford F series in the US.

[mnkeeking]

eatonsprings.com, ask for Mike. You have that info already, looks like, and these guys are some of the best. Should be able to help you.

Take care,
Joe