I think the Owner Occupier relief was 50% of the qualifying costs for 10 years (I'm basing this on experience of S23 relief when I lived in a Tax Designated county). I would have thought it was 50% of 160k, over 10 years. This would be 8k per year.
This would mean you would be able to earn 8k more per year tax free. So how much you get back would depend on how much tax you paid and at what rate you paid it. If all your tax was at 20%, I'd say you'd get about 1600 back. The max you could expect back would be 41% of 8k, about 3,200. If you paid less than 8k at the higher rate, you would get back somewhere between 1600 upto 3200.
I'm no expert at this but I think that's generally how it works.