I blitzed an interesting Diemer-Duhm this morning - lucky I knew the DDG theory up to move 13.
1.d4 d5 2.e4 e6 3.c4
I always try this against the French, even if it seems far weaker than the Blackmar Diemer lines
3...dxe4 4.Nc3 Nf6 5.f3
A strong move by black - often called the refutation of the Diemer Duhm
6.a3 Bxc3 7.bxc3 00 8.fxe4 Nxe4 9.Nf3
White seems to have less than nothing for the pawn - but now white's preparation comes in handy.
9...c5 10.Bd3 Nxc3
10...f5 was the other good option
11.Qc2 cxd4 12.Bxh7+ Kh8 13.Qf2
White unleashes a violent attack
13...Kxh8 14.Ng5+ Kg6 15.h4
My silicon assistant indicates that 15.Qg3 is better, eg 15...Kf6 16.Nh7+ Ke7 17.Qxg7 with a decisive attack.
15...f5 16.h5+ Kf6 17.h6 Rg8 18.hxg7 Rxg7 19.Rh6+ Ke7 20.Qh4 1-0
Obviously black's play was far from perfect after move 16, but I guess this game shows the tremendous attacking chances in the Diemer Duhm Gambit - but expert knowledge is certainly needed to be succesfull in these lines.