This is my first draft of calculating the chances of living forever - no doubt it will be updated many times - and I'm happy to say I've got a 1 in 10 chance even as a middle aged man. This is a first guess based on assuming 20 years before all the big killers are blighted, then another twenty to slow aging down to zero. This introduces the concept of physiological age - i.e. the equivalent age of my body rather than the number of years I have lived.

Using the UK mortality rates, which increase with (physiological) age - after 20 years even though I'm unlikely to die of disease, old age has crept up to reduce the chance of me surviving for another year to 97% and by the time life extension technology as stopped aging entirely I'll have a physiological age of 72 (though enjoyed 83 years by then) which means only a 94% of surviving each year. If life extension technology then turns into rejuvenation technology then I could bring my physiological age back to to 30-something (120 years) where I'm more likely to die from an accident than my age.

Here is the table of figures - I'll annotate and provide sources etc over time.