From Johanobesus:
I don't believe we ever actually saw a D7 firing in TOS...
Incorrect. In the TOS episode
'Elaan of Troyius', a Klingon D7 battlecruiser fires green pulses from the nacelle tips, or possibly nacelle pylons. It's not very precise on screen, but it's generally accepted that it was firing from the nacelle tips.
In TOS, the Klingon/Romulan battlecruiser was never seen to fire PhoTorps, and SFB has the Klingon Navigational Deflector/Long Range Sensor disk in what came to be the forward torpedo tube of the
'STI: TMP' K't'inga-class.
In
'TMP', a K't'inga fres three red PhoTorps at V'Ger from the forward tube and two of them from the aft tube.
The three K't'inga's in
'STII: TWoK' were reuse of the
'TMP' footage, so they are firing standard PhoTorps from the forward tube.
The only other time we saw a D7/K't'inga-class arming/firing weapons in TMP-era was the
Qo'noS One in
'STVI: TUC'.
Kruge's BoP fires yellow torps from the command pod tube in
'STIII: TSFS'.
Klaa's BoP fires yellow torps from the command pod tube, and 'pulse phaser'-style disruptors from the wingtips in
'STV: TFF'.
Chang's experimental BoP fired standard PhoTorps and no disruptors in
'TUC'.
As for the TNG/DS9/VOY stuff... well, I'm a Classic Trek fan. Didn't pay that much attention.
Hope this is of some help.