Well lookie here - a majority of the piston remnants were found in the sump - see the total weights
# 4 Piston - undamaged = 593 gm - I'll assume this is a normal weight
# 1 Piston without any carnage = 554 gm 93.4 % of oscillating mass remained
# 1 Piston with Aluminum chunks found in sump = 574 gm
# 1 Piston with all parts found associated with it = 581 gm leaves only 12 gm unaccounted for or 2% lost.
It looks like it escaped into #5 > 2> 4 via the CIS judging from the head and piston dents. I may find more in the case when I open it soon. The connecting rod looks unscathed so far.
I loosened up my case bolts a turn or so tonight and as most of the 15 mm through case bolts on the top were lossened there was a sharp snap or click sound. Is this typical and what might it signify?