I too have SiFab radiator fitted to my 2013 Plus 4. Superb build quality, should have been a standard factory fit. Which leads onto the question, why weren't they?
I wonder what percentage of the trads built in the last 5 years or so, have had to have have a new radiator fitted? Assuming that a properly maintained radiator in a normal mileage vehicle should last 8-10 years. Should be very few.
Experience would indicate the opposite is true.
When mine failed at 3 years of age and 5k mileage, the response from the factory was a shrug of the shoulder and a "not our problem".
Maybe Simon would care to comment
Out of the 120 odd Morgan radiators I made last year, 39 were replacements for the plastic tanked post 2008 radiators
Simon @ SiFab.co.uk