OK, maybe we can put some of this to bed here. Although the war was not as hopeless in 1943 as it was in '44 it was still pretty well lost. Now after doing a bit of reading I gather that there were two valkyrie attempts in 1943, one in march and one in november(if there were any others please inform me). Now if you make the november one successful then forget it, kurst was already over and the war in the east was just a formality at this point. Now if the attempt in march succeeds then you may effect things, but as I will explain in a bit, it may in fact make Kursk go worse for the Germans.
So lets assume that the attempt in march succeeds, now the conspirators had plans to deal with all the hard liner top brass afterward, but in reality as military men know a plan rarely survives contact with the enemy, so it may be possible to get a clean sweep within a week of the assasination like the original scenario suggests, it was also possible for the bismark to get lucky and sink half the RN too, however it was borderline ASB. Most likely you will have at least one big wig survive and fight for dominance of the Reich for some time, not to mention all of the Waffen SS guys out there who are not likely to simply go along with the same Heer that just assasinated Hitler and the other Nazi elite they were fanatically devoted to. As such you will most likely see SS troops actually fighting the Wermacht(maybe not the entire SS, but various units across German territory). And I have no doubt that this will apply on the Eastern front, which will be really bad for the germans. I wouldn't be surprised to see the conspirators spending months rooting out resistance before they are secure, so it may be possible that there will be no central command of the German army, or even a coherent Eastern front when Kursk comes around. So we may be looking at not the tactical victory and strategic loss that we saw in OTL, but a total loss like Stalingrad was, at best the Germans wait longer as the build up for their offensive takes longer due to confusion at the top as well as likely supply issues resulting from the SS mutiny.
On the west things aren't likely to change, by november the Allies are already firmly entrenched in Italy, and march may result in too long a time of chaos for any extra preparations to happen in Italy. Air superiority should still belong to the Allies, assuming that the conspirators put more resources behind the ME262 that is irrelivant, no matter how many jets the Germans build it won't make a difference, they only feilded about 200 jets out of over 1400 produced. And no matter how much the conspirators distance themselves from the nazis and change plans for production it won't solve the manpower problems, or make the ME262 require a shorter runway, or give the Germans more oil. The only thing that may work out better for the Germans at this point is that the Wermacht will probably be allowed to send tanks from calais to reinforce the forces in Normandy, however, this is no guarantee of German victory, especially considering that casualties OTL were about half of what was expected, so there is still a good chance that even with the extra armored support the Germans still wont inflict enough damage on the allies to defeat overlord.
As far as the home front, for some reason people assume that the american and british people would be all to willing to sue for peace at the earliest possible time. Using the Vietnam war as an example is actually counter to the argument that a peace movement would gain ground so quickly in the US and UK. Vietnam took a decade of fighting with no real provocation or war aims as well as three presidential administrations before the US pulled out considerably longer than WWII was. Besides, FDR wasn't up for re election until 1944, and he wouldn't actually be out of office until january of 1945 if he lost. By that time the war was virtually won, and any president who gets into office after FDR would be breifed on the existence of manhattan as such he would be almost assured victory in Europe within a year. In spite of any campaign promises, being a president who made peace in Europe is good, but being the president who won peace is even better as far as political capital goes.
In short, by 1943 short of ASB intervention there is very little that can happen to change the fate of Germany, with or without hitler.
Well, there's what I've been trying to write all damned day!
Good post.