I have measured the width of the window and I should have 1/4'' each end to fit it through. The place is rented and despite a so called preservation order, its in a terrible state of repair and barley holding together. I dont fancy dismantleing any part of this house even with permission, as I dont trust it isn't bodged in the first place.
If I go with through the window, I will probably have to do a bit of covert night ops as the only sash window left is the one overlooking the main road through the village. The path is narrow here so anything you haul up will be suspend over passing traffic, and might look a little suspicious.
Not possesing a 5mm punch I have one on order, just in case I go that route. I will post victory pics when done. Or just move house (planning that anyway) to somewhere with a proper workshop away from noisy roads.