I'd still contact Esselle. They may well be able to patch in a piece to lengthen the remains of the section (repairers do have some partial/old sections and may be able to find a piece that fits). Your chance of getting Maver K series spares are slim, I'd say - it's quite an old model. However, a lot of their poles were made on the same mandrels, so some sections will interchange. If you can find something contemporary (there were F, K, L, M and N series from memory) or similar, it may do the trick. Of course, you may have to buy the whole pole, but you can use your top kits with it and have spare sections up you sleeve in case of more accidents. About the only chance is to scan eBay, etc for old ones. Good luck with it.
---------- Post added at 05:23 ---------- Previous post was at 05:04 ----------
An additional suggestion. Fisherman's Friend in Birmingham have some older Maver models at clearance prices (you have to buy the whole pole, of course). I've found them helpful. Worth a call.