401 heater modification

[p5b401]

Investigation of a pax side leak from the heater found it to be a perished hose elbow - of which there were four.
The 401 spares book did not show my assembly and further investigation suggested that it was a modification.
The original heater matrix was in place but a further two heater matrix have been fitted and plumbed in serial fashion as per photo (most linking pipes and hoses removed for clarification).
I pressure tested all three and there were all good but plainly this would potentially pump out a lot of heat (with a window open or a cabin exhaust air vent fitted).
The car originated in NSW but is now in WA and with no experience of driving this car in a really cold environment, I don't know if the normal heater configuration need this kind of boost
Is this a Bristol mod or someone that got really cold?
Thoughts appreciated
John

[Geoff Kingston]

If I was putting a bet on it I would say this mod was not done by Bristol because the surrounds for the heater rads they used were alloy whereas yours appear to be steel and much more substantial, it is a very interesting modification, does it add a lot to the heat output.
I was not sure from the photograph if these were in their original location ( one each side in front of each door) or if they have been moved, especially as you mention there are 3 rads together, does the other side have one with the cowling for the blower motor to do the screen demisting?
Geoff.

[Kevin H]

Perhaps the car lived in the alpine region of NSW? Otherwise I would assume the mod was done in another (colder) country.