OTHER CONSIDERATIONS
With reference to the other sources, the above information are then accurate up to the Meyer's text (ref.D - 1925) that quotes "... un quadro rappresentante al naturale ..."  [... a painting representing life-size ...] and "Questo quadro si trova ancora nel Refettorio dei religiosi in Roma" [This painting is still in the Brother's refectory in Rome] , two right assertions that refer to the Picture1 (ref.G1). Meyer himself, however, wrongly quotes both the name of the author and the inscription on the back of the painting.
Here below is the real text (with the relevant translation) checked on the original, still located in the refectory of the Fatebenefratelli hospital

 Fra Gaspar David de Lahier a Gratianopoli
Religionis S. Ioannis Dei professus pingebat
in occasione quod
Clemens XI Pontifex Maximus ex Sua nimis Charitate motus
Pauperibus inserviendi ad praefat[ae] Religionis
Xenodochium se contulit die prima martii 1702
Ad perpetuam rei memoriam Patres posuere

Bro. Gaspar David de Lahier from Grenoble
professed of the Order of St. John of God painted [this]
on the occasion when
Clemens XI Pontifex Maximus moved by His immense Love
to serve the Poor went to the Hospital
of the above Order in the day first of March 1702
The Fathers put [this inscription] for eternal memory of the event

Martire (ref.E - 1934) wrongly refers both the paintings to the same event of March 1st 1702.
Finally Huetter and Montini (ref.F - 1962) combining the date 1702 indicated on the back of the Painting1 and the image of the Painting2 in which are represented the arch of the Assunta Hall already completed and on the background the two semicircular staircases and the new hall, concluded that also the completion of the Assunta Hall was to be "... ristretta al primo biennio del pontificato clementino ..." [... limited to the first two years of the Clementine pontificate ...]