Can you help to identify these frames, bikes or parts?

Over 2kg for a 55 frame it's definitely not an SL as far as i know.
You don't have to feel disappointed about it's weight, you will gain
more stiffness. Many beautiful bikes are close to 2kg.

As concern the fork, just avoid to have one with its' blades been more
aero than 1.5cm (~1/2" ). Of course you can always have a pricey and light
columbus minimal 1" since you will built it with modern parts but you should
know that is a "race" fork and some people find its' feedback rough
depending on wheel-tyre characteristics.

Every bicycle that makes us happy, collect water or moisture through seatpost
or bb cups at wet conditions. Steel bikes should always have drainers to avoid
corrosion from trapped moisture at lower ends.

you will easily notice those that i propose for stays on plain steel bikes
that need them most. Drainers are a "detail" or an "extra" feature that usually
be absent on "team" ordered bikes cause they are cheaper priced and no one
believes that will last more than 4-5 years to protect them.

You should measure seatpost lug on two basic axis.
First measure the longitudinal that changes more difficult and it's more
accurate. Then measure the transversal that commonly changes if you had
a smaller seat post than you need.

for example; if you measure 26.88 the transversal axis will likely need to open
both sides (or the one that bends more) to gain 27.2 like the longitudinal
and the cutting faces should be parallel.
In that case you need a 27.2 seatpost that will insert tightly in lug.

You can refresh - clear ST using a half of a sanding sponge (n80)
from a hardware shop along with a piece of hard cable.

please excuse my english :)