Were they living beings, then? Actual birds, with magical and mechanical changes?
Correct. Of that the party’s Wise and Knowledgeable can agree.
Ghan is not impressed with this alteration of Nature.
He keeps the 2 Conjured Eagles for an hour to act as flying scouts / guards
“Abominations! That’s what these are. A perversion of the art. Imbuing mechanics into willing living flesh is already pushing the limits of propriety, but no living being should be forcibly imbued with mechanical features, and I highly doubt these birds had enough awareness of self to consent.”
Ceol examines one of the birds, nodding in agreement with his companions.
“In Rohan, stories are told of how Saruman created the Uruk-Hai that he sent against us at Helm’s Deep, using his wizardry to twist and modify their forms. This does seem to be yet another of his perversions of the gift of life which Eru Illuvatar alone can provide.”
Thoroncir declares, “All the more reason we must stop him, and soon, before he or his followers may commit any further crimes against life, nature and reason.”
The party makes it to within 20 miles of the Gnomes. According to the machine, Saruman is still there. Though it seems like he is far more active now.
Your closest potential allies are on the other side of the Sea of Rhûn. The Wood Elves of Belam the Bowyer.
Gnomes are labeled 3
(How far away are the elves in Taur Romen? Given that Saruman is already active, we may not have time to spare to meet with the elves first, but it’d be good to know how far they are, in case we need to attempt to call on them.)
About 260 miles, as the Eagles Flies. So very far.
So we are on our own. That’s fine, I like it that way.
First things first we need to properly scout the area. I’m sure we don’t have the element of surprise on our side, so we will need to be tactically strong.
Who can we send to scout? Birds and probably someone on land.
Ghan can offer a Pass Without Trace to any party scout.
His Eagle Windwing can offer an aerial view (if Windwing sees any flying dangers e.g. a Dragon 
), the bird will return immediately.
"Suppose we send the birds out to scout the area, and determine how near we can easily get as a group. Once we’ve done that we can send one or two people forward to sneak around under cover of invisibility and see what we can learn of the layout from the ground. Once we get that information we can plan our assault.
"I don’t mind being one of the scouts. I’m trained in stealthy movement, and have recently mastered the art of moving in armour without making more noise than if in plain clothes. Add to that my gifts of cloak and boots and I won’t easily be noticed.
"That being said, I am a slower walker than everyone else here, so I can’t cover as much ground and would find it harder to escape if chased.
“Our friend Ghan’s offer of Pass Without Trace is also a good one to consider.”
After having snuck past half the party while they were distracted by Windwing, Ninthel throws back her elven cloak revealing herself on Felareth’s left just to show off how stealthy she is. “Some may say that I am an expert in stealth. I would be willing to go ahead.”
“Ghan, would you be able to send a message via bird? It wouldn’t be immediate help but some nearby backup might be nice.”
"I agree, some stealthy scouting is our first step. Anything we can learn about his defenses, troops, and the location of the fallen wizard himself will be useful, as well as identifying feasible routes for us to approach.
“It’s likely safe to assume that Saruman knows that we are coming – or, at least, that someone is coming. Also, as we have his device…is there anything that we can learn through it?”
Ghan thinks about this sensible request.
He could use Locate Animals, then Speak to a nearby bird and finally cast Awaken on the bird - giving it reasonable intelligence and the ability to speak one language (Westron? Silven?)
However the casting time is 8 hours. 
(DM, could we assume that the party foresaw this situation and that the spell was cast yesterday? 
)
I will allow the awaken.
So Ghan has completed his trio of spells/abilities:
- Locate Animal (a nearby bird, preferably a fast flyer!)
- Speak to the bird to get its permission to Awaken it
- Awaken the bird, giving it intelligence and ability to speak a language
Ghan asks the party for recommendations:
- what language should he teach the bird? (he can offer Westron or Silven)
- where should it fly to? (presumably the nearest Elves)
- what message should it deliver? (presumably the bad news about Saruman - but whereabouts should the Elves look?)
It’ll help us figure out the most direct route to where he is, which might allow us to bypass some of the outlying forces, but I doubt it’ll be much help in preparation for any encounters with the Enemy.
“Ah, Lady Ninthel, if you re that keen to sneak around in the foe’s backyard I will not say thee nay.”
Turning to Ghan, Felareth continued “I would advise Wetron over the Sylvan language, as Westron is much more widely spoken. Unless the intention is to deliver the message to an isolated community of Wood-elves, in which case Sylvan would be better.”
When the scout(s) head out Bitur could just move the machine about a mile North or South and verify position pretty precisely at this point.