Classic & Vintage - 2 brand identification questions

I am having problems identifying some parts that I pulled off a NOS Nishiki Olympic 12 that I bought. I'm fairly certain that it is late 70's/early 80's from the decals...

There is a fluted seatpost that is JIS stamped and has an SR marking on it. the S is above and to the left of the R.

The other is a quill stem. No markings on the clamp. I'm trying to figure out the markings, but it could be JIN or WIN, also JIS stamped. There is a set of road drop handlebars with the same brand marking on one side of the clamp area and "Winpista" on the other side.

Any help is appreciated. I can dig up my camera and post images if that helps.

SR Is or was Sakai or Sekei (sic) Ringyo??A big Japanese parts manu.The others are almost certainly Japanese parts-but no news there.Luck,Charlie

I believe the stem is a Custom. I had a late-'70s Olympic last summer, and the stem was exactly like another Custom I had, but without the name embossed.

SR (Sakae Ringyo) and Win are correct. Nishiki used this combination of products products over a long period of time, from about the mid-1970s though the mid 1980s. I've got a database for Nishuiki serial numbers, so I wouldn't mind knowing yours. If you could post some pics of the bicycle, that would be great.

I'll check the serial numbers when i'm home for lunch and post some pics....I've gone only on decal matching and paint schemes until now, but it would be great to know a more exact year.

//edit
Here are some pics from a few months ago, it's been converted to fixed gear although i still have all the original parts like the cranks, stem, seatpost, BB, handlebars. I bought it only as a frame. I've changed it a bit since then. Let me know if you have other pics that you want. Everything has been switched out except the headset (original) and frame.

Checked the Serial on the BB shell - KA 08429

Based on my current understanding of the Nishiki serial numbers, I would have put it about 1981. However, for 1981 I would have expected a decal as opposed to an actual headbadge. If you still have the original parts, many of them may have date codes which you can decypher using the information on http://www.vintage-trek.com/component_dates.htm . The SR seatpost should have one. If you date the components, I would be intereseted in knowing the results.

The Sakae seatpost has E-81 on it, and the Sugino cranks have A-5 stamped on them. Both these schemes point to May 1981 according to vintage trek.

The stem that came with it was a WIN stem. There are a couple of stamps on it:

WIN
9886 (JIS) E C
Max Height Line
Japanese Characters
Japan 22.2