Let me know how that goes, I also passed in 2001 and want to upgrade my entitlement at some point.
I have the application form and medical done so far. Not posted my licence off as I'm needing to hire vans pretty regularly atm. When I spoke to a training provider in Northants, they reckoned that C1 and C were pretty similar in terms of difficulty, but adding the E made the C significantly more challenging than the C1 as its basically the difference between a Transit & Trailer vs a full on artic.
That's down to the rest loop holes... For the C1, it only needs a GVW of over 3.5t, where as the C is at least 12-18t.
Given that the five part test is the same in every way, pay the extra £200 and go straight for the C