I have a Lockwood combination lock with 140/50 stamped on the back, probably the model number. I know the combination and until recently it worked two out of three times. As it had lain in the shed for about a year without use I thought it might have got a bit of dust in it so I lubed it with WD40. Little or no improvement so I flushed it with kerosene which seemed to improve it a bit. Now after leaving it lying in the shed for a month or two I can't open it at all.
Any suggestions, apart from chucking it.
