Having also been up the ladder recently, I agree with what alexchien says about it above.
Just been discussing this with another forum member. There is, of course, the option of installing a replacement ladder made from stainless steel. Not cheap - but anyone who has used the equivalent item on Peak Cavern's Surprise View pitch over the last decade or two will realise that it's a very good long term solution.
As there are various reasons why folk may want to ascend the pitch up from the end of Hensler's Passage but not have SRT gear with them, on balance I'd favour a ladder rather than a rope. Ropes need regular inspection and occasional replacement, so the rope option brings with it a maintenance burden and potential ongoing costs. Spending some money on the stailess steel ladder option would sort it for the next 2 or 3 generations of cavers (at least).