So apart from the different landing gear, different wheels and the lack of folding tail boom the height of the Mk3 is just like the Mk1…
Again, I've no idea about the hangar but the photo of a Mk1 on jacks with its tail folded does not provide the answer. Photos can be deceiving but the rebuttal photo does appear quite close to the overhead structure I would be surprised if the clearance remaining would allow for an un-folded or non-folding tail.
Not a great deal of clearance when not on jacks - again, tail boom folded:
