bob No luck yet! I've had a quick look over lunch "al desk-o" but have another meeting to attend soon. I'll look at it again this evening and report back tomorrow (if it has not been solved in the meantime). Cheers!
Counting columns 1 to7 from the left, method of solution:
D = 1 (col 7); S + E = 9 (col 1);
S + T = E + 9 (col 6) probably
G+ A + L = 9 or 19 (col 4) probably