Tawny-faced Quail at Calle Maipo

After spending 2 frustrating days trying to see the Tawny-faced Quail at the end of Calle Maipo at dusk, hearing them but not seeing them, yesterday (Sunday) we decided to play back the call at about 3.00pm. Much to our amazement, we got responses. Having called one bird in to spitting distance without seeing it, and then losing touch we went on to look for easier prey such as tanagers. I then heard a quail calling back along the trail and went to investigate. This was an areawhere you can see into the undergrowth. I first saw two small birds on the opposite side of the trail from the one which was calling. They walked quickly away, but I was able to clearly see the brown wing coverts mottled with buff (or grey?) and darker brown (or black). The pattern was clear, but it was not easy to determine the exact colours in the shady undergrowth. The other bird was giving the single note call; when I eventually located it it scurried off which did not help in getting a good look; nevertheless the glimpse through binoculars revealed an orange-sided head which really showed up in the shade.
The birds were smaller than Black Eared Wood-Quail, behaved differently and did not call as those wood quail do when alarmed or separated (we had such a situation once at Nusagandi). Also, the whole face of the male I saw showed orange, rather than just the characteristic topnot of the woodquail. Marbled Woodquail is considerably bigger.
While the male gave the single note call, the birds on the other side of the trail could be heard to give the complex "questioning" call of 5 to 7 notes. No conclusion can be drawn yet but I wonder if these are location calls and different sexes give different calls. According to Howell in Birds of Mexico, Stiles and Skutch 1989 reported "a sad, ventriloqual, dove-like cooo or toot", which I suspect is the call heard form a distance, since as you know the single note call, close to is really tinamou-like.
Unfortunately nobody else in the party was in the right spot at the right time to see either of the above species. I must say that the illustration of the [Stripe-throated] Wren in Birds of Colombia is much more realistic than the one in Birds of Panama. Likewise the illustration of the quail; Gwynne must have used some really moth-eaten old specimens for his illustraton.