I have this piece below that I got in a lot from Salvation Army.  It included a load of really vintage Lego and Duplo pieces.  This piece I cannot identify.  It is 16 studs long, and is jagged on the top like this rip cord piece http://www.bricklink.com/catalogItem.asp?P=11126

 

I cannot find anything similar on Bricklink or Peeron, and not sure even how to search other than the length as I can't appropriately describe the top of the piece.  The second photo is just to show it is a Lego piece

 

(Edit: I should also mention there is no part number on the piece.)

 

It is one of the earliest train track pieces Lego used when they introduced Trains to their lineup back in the day. There is the one with 'teeth' same as yours here I believe while another is completely smooth. There are a couple different versions which only add to the frustration of narrowing it down perfectly but I do know it is from the original Lego train sets simply for being the color blue and was used up until the late 70s.

it looks like this piece:  http://www.bricklink.com/catalogItem.asp?P=2428

 

but it's a weird color

It is one of the earliest train track pieces Lego used when they introduced Trains to their lineup back in the day. There is the one with 'teeth' same as yours here I believe while another is completely smooth.

This helps a lot, thank you! Thought I had searched all 16L and 1 x 16 on BL, but I must have missed it.

This helps a lot, thank you! Thought I had searched all 16L and 1 x 16 on BL, but I must have missed it.

Always happy to help.

A grey version of this piece is also used for the monorail in this set: http://www.brickpicker.com/bpms/set.cfm?set=6970-1

I still have this set somewhere in my parents' attic.

 

Edit: Upon closer inspection, it seems that the 6970 set uses smooth pieces rather than toothed ones. Oh well, this brought back memories from when I was 4 years old which is pretty cool.