A Belgium on the Allied side since October 39! It's really a boost for France. Basically the Dyle maneuver was a desperate attempt from the French high command to restore the defensive belt they lost when the Belgian got neutral.
I expect that there will be some sort of integrated command on the Allied side, but even if there isn't one, it will be infinitely better than OTL. There was basically no contact between the French and the Belgian outside some secret ones. For instance, France wasn't made aware that the Belgian changed their plans in the Ardennes and didn't intended to cover the sector (ouside some light troops).
But even now, I think the German should try the Sickle Cut. It's the simplest way for them to avoid a WW1 style campaign and associated the attrition they can't support on the long run.
A few side remarks :
FCM 36, Renault D2, and the Renault NC were to be discontinued leaving only the Renault R35/40
FCM-36 was discontinued in 38-39 after 100 or so were delivered.
Renault NC was discontinued in the early 30's!
The last batch of Renault D2 was at the end of delivery, so it's really likely that the production will stop no matter what in June or July.
Renault had switched from R35 to R40 on the production lines in the spring (Mars or April). The R40 tank have an improved gun (37 mm SA 38), giving it a real anti-tank capacity. It also have improved suspension, giving it far more reliability.
I agree with you for the B1 and the S-35.
You have forgotten the H-35/39! It's the light tank used in the armored divisions (DCR and DLM) because they were faster than the R35/40. As such, they had priority for the 37 mm SA 38. The goal was to produce 300 H39 a month from October 1940 onward. By the way, the H39 was selected for an industrial pool with the British and the Portuguese.
https://en.wikipedia.org/wiki/Hotchkiss_H35#Operational_history
On France ordering aircraft from the US, they have really important orders already coming in :
https://en.wikipedia.org/wiki/British_Purchasing_Commission
OTL, France had already bought 120 B-24 as LB-30. They will possibly expand the command, but no B-17.
75 Vindicators Dive Bombers from the US
France has already received 40 and they have a further 50 in order, so it's possible for the Navy.
But don't forget the french made LN-401 and LN-411 (
https://en.wikipedia.org/wiki/Loire-Nieuport_LN.401). They have only one crew, which is a bonus given the scarce manpower of the Armée de l'Air. Their biggest problem is that they use the same engine than the D-520.
OTL, both types were trounced by the Luftwaffe (dive-bomber are very vulnerable if the airspace is heavily contested).
300 Vultee Vengeance were also on order.
Havocs ordering 150 of them
Also already on order, along
Glenn Martin Model 167.
Edit : After reading your entire timeline, I have a few more remarks :
I think you get the German to deeply in France.
If the Heer is in Cherbourg and Caen, it means that the Seine has been breech, so Paris is untenable rapidly. Plus, the way you describe the Eastern France Front going from Dijon to the Swiss border means the Maginot Line is completely lost and, with it, the whole north-east of France. It's something that France and it's army can't recover from (as a significant fighting force).
Don't get me wrong it's possible to breach the Maginot Line, but OTL the German did it after the French Withdraw all the interval troops and artillery. And I think ITTL the German will use those forces to breach the Front in Belgium.
All in all, I think that their will be a line on the Somme in the West, like OTL. They will breach it and take Le Havre, but the Allied counter-attack will isolate the spearhead.
In the East, I can see the German going deep in Champagne, taking Reims, Chalon and even Troyes
I think you said 1940 instead of 1941 in all your posts since that one.
I don't know if the Burmese Road will be that predominant, there is, after all, still a railroad open from Haiphong into China.
If anything, the Japanese will probably attack this one first.