Sun Roof

[will7262]

I see there is a photo, page 354 in Bristol Cars a Very British Story, of Blenheim 3's in the factory without their roofs. There are three roof supporting metal straps shown. The gap between the window head strap and that at the B post might be just big enough for a small Webasto.
This of course assumes that the roof of the 603 is constructed in te same manor. Given the nature of Bristol this is of course unlikley.

As for earlier models this form of roof construction might also be the same.

I will let you know the outcome.

[Ronald G. Stephenson]

The understructure on the Bristol roofs is likely to be small diameter tubing, as is the practice on aluminium bodies, but they may have fabricated a flatter 'slat' sort of thing in an effort to make more headroom, but it is a simple matter to re-inforce what you have with additional material to surround the new opening. Trust to the people who you select to do the work, and ask questions as to how the do it, and by all means, look at some of their work before you commit. Good luck.

[Janne]

Closest to the front and rear windcreen it is a round steel tube. I do not remember the rest, but it would surprise me if they were flat, as the rooflining would not be as flat.
The people cutting through it need to be very skilled, if they make a misstake and the roof sub structure is weaked, or get a different stiffness, the roof can start to move/vibrate and then you will have a problem.

The construction Bristols have is a modified Superleggera on a "standard" stiff Chassis
The Superleggera principle is very sensitive to changes.
Yes, the chassis is stiff, but the body is not.

As I opted out from a sun roof myself, I am not sure if they will fabricate drain channels or how the water is drained away?