Looks like there are several options available in HO scale.
While this picture isn't the best, this ALCo S-1, on the Kiski Junction Railroad, in Schenley, PA. has an eagle casting atop the bell hanger...
Wayne
Check out this link.
http://www.railroad-line.com/discussion/topic.asp?TOPIC_ID=21628
A reference is made to Musket Miniatures Rustic Rails HO Scale Eagles which can be found here.
https://musketminiatures.biz/products/hoc3875-eagles?_pos=1&_sid=b32d34ff1&_ss=r
This may require some additional research, but I hope it helps.
Rich
Alton Junction
Does it have to be an eagle?
This set from Preiser seems to offer a candidate or two
https://www.walthers.com/pigeons-seagulls-crows-birds-of-prey-22-pieces
Or Noch's similar set
https://www.walthers.com/birds-nests-12-birds-3-nests
I wonder if a simple bird shape of very fine wire, covered by solder which is then gently filed (or squeezed for the wings) would come close enough?
Dave Nelson
For those unfamiliar with the eagle in question: it was conserved right through the 21st-Century restoration, and you can see it (unfortunately without any 'backstory' on its history with 385) here:
http://www.whippanyrailwaymuseum.net/exhibits/equipment/41-facilities/museum-equipment/86-steam-locomotive-no-385-page-4
I think you could easily scale the necessary size from these even if someone with better closeups or access to the locomotive during the current crisis closure can't provide better views.
It might be worth looking into some methods of casting to make one of these eagles with appropriate sturdiness to be applied to a model that will be handled and operated.
Shapeway might have one, or you could look at Preiser. They have a number of flying hawks you might be able to adapt. Military miniatures from a flagpole, perhaps?
It takes an iron man to play with a toy iron horse.
http://www.rrpicturearchives.net/showPicture.aspx?id=3900368
In real life it was a scaled down eagle. In HO scale you would need N scale or smaller. There can't be very much demand for that, I suspect you are going to have to carve your own.
Henry
COB Potomac & Northern
Shenandoah Valley
The Morris county central RR in the 60's ran Southern Rwy 385 . I only got to see her shortly after I was born in 72, some time before it's demise. I just purchased an ho scale 2-8-0 by Bowser and I am seeking an eagle that sar on 385's headlight . I have searched with every algorithm and keep coming up empty. Does anyone make them that small? Please point me in the right direction. Thanks in advance.