Mechanic put a Magneti Marelli glow plug in a VP MD2030a few years ago, I saw that it had the number UC59A on it, it lasted me two years and I was satisfied. Now he put some Febi and it only lasted half a year.
I looked in local stores and they don't have UC59A (cat. no. 062900077304), but they offer a similar one (UC46A cat. no. 062900063304), which according to the specifications is 0.5 mm longer. Could this difference do some damage to the engine?
UC59A
https://www.autodoc.co.uk/magneti-marelli/7067531UC46A
https://www.autodoc.co.uk/magneti-marelli/1825486