Philately - faulty stamps

[George38]

About 10 years ago, as a serving SubPostmaster, I came across a sheet of 100 x 37p golfing stamps that were faulty. The ink had obviously run during printing in the middle of the sheet. Never having seen such a fault before or since, I decided to buy the whole sheet (�37 worth!), and still have them to this day.
What I was wondering was, provided the fault is genuine, i.e. caused by faulty printing rather than tampering with chemicals (and I have no reason, considering how I aquired them, to think otherwise) what they might be worth, other than their face value.
Any ideas anyone??

[Everhelpful]

I would certainly be taking them to a respectable Stamp Dealer for a valuation. Don't take 1st.valuation,shop around. Good Luck.