Hmm a little grim on the topic of IMC flying courses... But poignant learning point I guess!
I think that flight was doomed from the moment the pilot considered attempting to "have a look" at Elstree when the reported visibility was only 800m on the ground. Even if there was a radio mast that could have acted as an NDB, doing a non-precision approach doesn't mean that you can land on instruments it is merely a means to align oneself with the runway until you break free from the cloud base at a minimum safe height, then proceed to land visually. Not sure how 800m visibility warranted an attempt.
What myself and others were referring to, was going through the cloud base that could have been at say... 1000ft or even up to 1500ft (a sensible height), use an approach elsewhere to break through the cloud base safely and break off for a little VFR scud running up to Elstree (of course abiding by the 500ft / glide clear rules). Which can and has been done safely many times before.
As I said though - I'd divert to Southend, do the ILS and take the train back home. It may not be the most convenient, but you can't beat being safely on the ground, and only a 50min train journey to Liverpool Street.