Hi all,
I've got permission from the big boss to publish my solution, here it is
Ciao
Bruno
Starting grid:
Q9 19+9+10=38 -> r7c9 = r9c6+7
R1/R2 31+18+22+13+14=98 -> r3c9+r4c9=8
R9 5+16+19=40 -> r9c1=r8c5+5
C6/C7/C8/C9 22+14+15+26+16+3+18+18+9+10+19=170 -> r1c6+r1c7=10 -> r1c5+r2c5=8
if r1c5+r2c5=[26] -> r1c6+r1c7<>10 -> r1c5+r2c5<>[26] -> r1c5+r2c5=[35]
R1/R2/R3/R4/R5 31+18+22+13+14+18+16+12+15+26+15+7+3=210 -> r5c4+r5c7=15 -> r5c4=[68] -> r5c6=5
r3c5+r4c5=max 6 -> r3c5=[124] r4c5=[124]
r5c5<>8
R1/R2/R3/R4 31+18+22+13+14+18+16+12+15+26+15=200 -> r5c3+r5c5+r5c6=20 -> r5c3+r5c5=15
R8 16+10=26 -> r8c1+r8c5+r8c6=19 -> r8c5<>1 -> r8c1=[6789] r8c5=[6789]
1 in r3c5/r4c5 -> r5c5<>6
r6c1+r7c1+r8c1+r9c1=18 -> r6c1+r7c1 max 5 -> r6c1=[12] r7c1=[1234]
R2 13+14=27 -> r2c4+r2c5+32c9=18 -> r2c4+r2c9>=13 r2c9<>8 r2c9<>6 r2c9<>5 r2c9<>4 -> r2c9=[79]
r2c9+r3c9+r4c9 min 15 -> r1c8+r1c9 max 7
if r6c8/r6c9=8 -> r6c9/r6c8=1 (invalid) -> 8 in r4c7/r4c8 -> 8 in r7c9/r9c9
r7c3+r7c4 max 6
if r6c6=2 -> r7c6/r8c6=[79] Conflict r3c6 -> r6c6<>2
r6c6+r8c6 max 13 -> r7c6= [6789] -> r7c7/r7c8=[45]
At this point I was making some more thinking without noticing the single 5 in r9c4, but Gabriele promptly corrected me, the 5 in r9c4 solves the grid. Danke Chef