The above is for the bomber side of things.
Now, for the missiles... even flawed because LOX, the French would gladly grab Blue Streak as an interim IRBM. There is no doubt about that.
My readings of the MacMillan - De Gaulle - Ike-JFK triangular relationship 1957-1963 clearly show that, when ELDO and Europa happened in 1961, the French were trying to grab Blue Streak and bring it back to its IRBM status.
Have a look at this.
De Gaulle had one of his advisors (De Rose) secretely discussing with your Thorneycroft (of TSR-2 fame) to try and pass some Blue Streak and nuclear secret to France and accelerate the Force de Frappe missile deployment.
That guy, exactly
https://fr.wikipedia.org/wiki/François_de_Tricornot_de_Rose
Thorneycroft was one heck of a colorfoul character. Had Nassau failed, he was ready to push MacMillan toward the french. Between 1960 and 1962 he was actively discussing with the french to look into possible nuclear cooperation with them. He was the one laying the groundwork just for that, as "Plan B" if a) Skybolt was canned (it was) and if b) Polaris could only procured via NATO / MLF / dual keys strings attached to them. And at Nassau the British had to bargain harsh to avoid the " b) " scenario.
But MacMillan was painfully aware the 1958 agreement expressedly forbade that: American repraisals would have been harsh. So MacMillan many times had to reign in on Thorneycroft activism and remind him not to cross red lines as fixed by the Americans in 1958. Of course the French loved that and tried to drag Thorneycroft BEYOND these lines, including with De Gaulle bait to MacMillan "nuclear secrets versus GB into the EEC". Poor MacMillan ended squeezed between a rock (the americans) and a hard place (De Gaulle).
It was against such background that (what a coincidence !) the British actually proposed Blue Streak to the French... (whaaaat ?) : as a CIVILIAN SATELLITE LAUNCHER. Within the frame of ELDO, hence with many other countries. By 1962 that was a go. But make no mistake, ELDO civilian nature and the 1958 agreement ensured the French could not move Blue Streak back to its earlier IRBM mission. There was a true "Berlin wall" between "Blue Streak as an IRBM" and "Blue Streak as Europa". The Americans were all aware of French shenanigans to get across that wall.
What the French exactly did between 1958 and 1963 was
looking for some kind of "loophole" into the 1958 US-UK nuclear agreement. Once that loophole found, they could snatch US nuclear secrets through GB without the latter country being sandbagged by the Americans.
Unfortunately for the French the US were no idiots and that 1958 agreement was, quite simply,
bullet proof. The French never found that loophole hence, had GB passed any nuclear secret to them they would have screwed the agreement, with the according punishment (think Suez crisis two years earlier, and the threats on the British pound... gasp ! - that kind of economic / monetary punishment).
One such example was the guidance system. Blue Streak inertial system was expressedly removed from Europa, to the french dismay as they badly needed it for FDF missiles. So they tried to get it back, but the british told them the 1958 agreement would not allowed such tech transfer. And on and on it went, the same way : reentry vehicles (NO !) engine technology (NO !) and on, and on. The French were driving Ike, then JFK, crazy.
Now, ITTL the masks have dropped and the French happily grab Blue Streak to provide the FDF with an off-the-shelf, unexpensive capability.
But that LOX oxidizer is really annoying. The Americans with Titan I and Atlas, the Soviets with Gagarin's and Sputnik R-7, had the same issue. So they are moving to storables (N2O4 oxi, N2H4 fuel - the latter Mark Watney beloved Hydrazine !) and toward solid-fuel ICBMs. So are the French with S-3 for Plateau'Albion and M1 - M20 for the subs.
BUT Blue Streak, just like Titan II, could be tweaked by removing that goddam LOX oxidizer for a better alternative. Blue Streak fuel is RP-1 that is kerosene like jet aircraft, and there is no problem with that. But LOX has to go.
And there, the British and the French each have a good option.
The British are the one and only using H2O2, not in Blue Streak but in every other british rockets: Black Knight, Black Arrow.
The French just like the Americans are moving toward hypergolic / storable, not for ICBMs but for Veronique and Diamant. There the oxidizer is N2O4.
Now, on the US side, Martin Marietta did such a move from Titan I (LOX / kerosene) to Titan II (N2O4 / N2H4). Aerojet had no problem with that: their LR-87 & LR-91 remained mostly unchanged.
Bottom line: the Blue Streak RZ-2 could be easily switched from kero/LOX to kero/H2O2 or kero/N2O4.
And once fitted with that new oxidizer, Blue Streak would regain its status as an efficient IRBM. The Soviets before moving to solid-fuel in the 1970's, did exactly that: they had IRBMs, ICBMs and even SLBM with liquid propellants.
Bottom line:
1964: a revamped Blue Streak with kerosene / N2O4 RZ-2 stands in alert as an early Force de Frappe missile...