Had a look at the accounts and here's the tale they tell
1994 the club had 2500 shares in issue which was upped to 5000 in that year (Johnson up from 1 share to 2497, so a kick in the backside of 10 mil cost for his share). In 96 there was a need to raise 15mil so this was done by a form of rights issue raising the capital from 5000 to 35000 underwritten by AIB Trustees who were Trustees of the Johnson family settlement, so any stock certs not taken up were bought by them for Johnson. Johnson acquired 21450 shares at £500 per share so £10725000 total investment by way of shares purchased from the club,.
Total outlay just shy of 21 mil.
Not certain, but I think he sold at 20mil to the consortium which valued the club at about 30 mil so made a loss, but I'll stand corrected.
I really should get a life