Oh dear this is such a sad event unfolding.It would bring a tear to every aviator if they found them all alive just awaiting rescue but it doesn't look like that's going to be the case sadly;-(.
Remember folks that this A/C & many like it where often faced with this same situation back in that era with pilots having far less experience than perhaps what we have here today. Low cloud, low performance machines unable to out climb deteriorating wx conditions all make for a very high risk event.
Flying in itself is inherently dangerous but it's the area beyond the cross-over point of acceptable risk that's always being challenged.
Obviously the pilot didn't take off with the intention of getting in a peril-is situation but experience is the single key to avoid these sad outcomes. Am sure we've all pretty much found ourselves somewhere wanting to be somewhere else when it comes to aviation so when these events happen & there will be more you can guarantee it lets all hope that we can learn from it/them so we don't find ourselves in the same situation.
The search must be very frustrating. One scenario here could be that the plane went into the think overhead canopy in a steep decent taking out the upper heavy foliage branches of the tall trees as it careered on down towards the forest floor bringing those same branches down atop the wreckage essentially camouflaging it, a situation that has had many a searcher over the years straining their eyes to see thru that vegetation.
Gods speed to the rescuers
Wmk2