I'll summarize the procedure issues one more time:
We don't know whether the back course of the localizer has sufficient fidelity to support an instrument approach procedure. But, let's presume it does. Same for the VOR radials west of the airport.
Let's say both the LOC and VOR are fine for Runway 12.
The terrain would support three instrument approach procedures:
1. VOR/DME lined up quite good with Runway 12 with either a teardrop course reversal or a DME ARC initial approach segment.
2. A LOC Back Course/DME approach to very good minimums with either a teardrop course reversal or DME ARC initial approach segment. Reverse sensing has been a thing of the past for many years with modern even 1960s HSIs.
3. A perfectly aligned RNAV IAP with a Baro VNAV vertical path for a precision-like approach. It would have to be a GPS aircraft for this third option. But, if not, the other two IAPs would be available.
#3 would have worked even had the other two not. If neither the VOR or back course are useable, then a separate front course or LDA type facility should have been installed years ago.
The fact none of these existed makes the country's aviation authority cupable to some extent in this tragic accident in my view.