Where are the conjunctions and prepositions here?

Question

In "The Markenmore Mystery" (1922) by J. S. Fletcher, the author was talking about a solicitor who was summoned to an ancient house, Markenmore Court, where an inquest was to be held after the death of one of its people.

Two days later, Mr. Fransemmery summoned to discharge the functions of a juror at that ancient institution, a Coroner’s inquest, found himself acting as foreman of twelve good men and true in the old dining-hall of Markenmore Court. That venerable apartment had been specially prepared and fitted up for the occasion; it was the first time, observed Braxfield mournfully, that it had ever been used since the grand state dinner which Sir Anthony had given to his friends and neighbours when Guy came of age.

Where are the conjunctions and prepositions here?

Shouldn't it be written as "to discharge the functions of a juror at that ancient institution, where a Coroner’s inquest was about to be held, and found himself acting as foreman

Answer 1

The word institution in that passage does not refer to Markenmore Court. The ancient institution is the coroner's inquest itself. This is definition 1c in Merriam-Webster:

a significant practice, relationship, or organization in a society or culture
// the institution of marriage

The sentence would perhaps be easier to understand with the insertion of two words:

Two days later, Mr. Fransemmery who was summoned to discharge the functions of a juror at that ancient institution, a Coroner’s inquest, found himself acting as foreman of twelve good men and true in the old dining-hall of Markenmore Court.

Even in the text as it stands, though, I'd've expected a comma after Fransemmery; its absence is surprising.