Van advantage

My client informs me that he has purchased some vans for his business. They were purchased second-hand from a 'mate down the pub' and the deal appears to be that 50% of the purchase price plus the VAT on full amount was paid up front with the balance being paid off by twelve equal instalments over the next year. The vans were acquired in March 2008 and accounts are prepared to the end of that month.

On acquiring the vans my client decided to get them sign-written and this work was done around the end of that month and payment was made in April 2008. My question is how to treat these payments for tax purposes.

Should I claim capital allowances on the full amount in 2007-08 or bearing in mind the new capital allowances rules could I claim only 50% in 2007-08 and the...