Brass HO Y6b help

[NW Modeling List]

Hi.

I am mostly a C&O fan, but certain N&W Steamers ring my bell too :)

I am rebuilding an old PFM Y6b and could use a little help with some
details.

In some pictures, but not others, of the prototype engine, there is a
horizontal tube located over the rear cylinder block on the engineers side
only. Could someone tell me what this thing is, and why it appears sometimes
and not othertimes ?

The particular model I am rebuilding come to me missing some parts. I have
remade most of them with better detail. But it was missing the smokestack
and the N&W used a odd forward canted, bolted base design on the later Y's.

Can anyone tell me where I might find a brass casting of this stack, or a
way to come up with something close ?

You can see some of my work here:
http://daveayers.com/Modeling/DTAModels.htm

Thanks,
Dave Ayers