These are some hirschfanger type swords in Vienna in a museum display which have been suggested 'of the type' often carried by pandours. The example on the left has a crossguard which seems reminiscent of the much heavier and workmanlike guard on the example we are discussing. It should be noted of course that the grip is of the familiar European hanger form of the mid 18th century and for quite a number of years later.
I would point out that the blade on this example in the Vienna illustration has a very curious clipped point. In Gerhard Seifert's 1962 book, "Schwert Degen Sabel" he has a group of line drawings illustrating blade sections and point types and terminology......there is a tip remarkably like the one on this Vienna sword which carries the term 'pandour point'. There was unfortunately no further material elaborating on the source of the term, but interesting to see of course the pandour term. Actually back in those days, I admit to being among those who had no idea what a pandour was !!
Getting back to Andys sword, it would be tempting to connect the guard to being of somewhat that style, however it is far outside the mid 18th century period in my opinion, and far too heavy to be considered of this type.
The 'pandour' use of yataghans would likely have been of traditional form, by the foot troops as previously noted, and these did not have guards of course....as noted as well, it is only presumed what kinds of weapons would have been used, but yataghans as far as I know did not have this kind of guard.
The hangers used by von Trencks forces, as shown by type in Buttin (1933) were typically of karabela type hilt, and did not have yataghan type blades.
There was apparantly a type of yataghan blade, larger and deep bellied, and believed to have been used by cavalry of European auxiliary troops modelled on the pandour units, from later in the 18th century. These swords seem to have had cleft yataghan style hilts of staghorn and were based on many of the hirshfangers of the period. One of these type blades is seen here in an illustration posted by Libra on a concurrent thread with an ivory hilt example but not associated with the units I refer to. The very large deep bellied blade I have seen before on examples that are believed to have been from these European units with troops from Balkan regions. The ones I have seen did not have this kind of wootz blade however, but typically were European made with cyphers and heraldic motif.
Looking at Andys example here, by what can be seen photographically, the age seems somewhat in resemblance to artifacts I have seen often while travelling through desert regions here in the southwest, most of which seem to date from about 1870s to 1900. This has the appearance of an item which remained static in an old building or such surrounding in very dry heat for a very long time. There is just enough moisture to bring rust, but intermittant heat to prevent dramatic overtaking of corrosion. That would be about the limit of my forensics skill

I personally think it may well be a theatrical item of those times, which though it might sound dismissive, I think these have a certain intrinsic value as period novelty items regardless.
A rough piece indeed, but still historic in its own right. ...and surely brought forward some great discussion on the pandours!!
All the best,
Jim