I think the estimates of numbers are possibly pessimistic, but there is no reason to be complacent. There is a lot of debate about identification and classification.
We are in one of the strongholds so it is quite possibly a pretty pure example, the white on its chin has previously been seen as a marker of hybrid, but is within the pure characteristics according to which 'experts' you believe.
The markings overall and the tail are pretty good evidence, and I have seen this one a few times now and would guess it is pretty pure.
When I was a kid we saw them almost every week, again we lived in one of the strongholds. Now we might see one 'now and then', so were very happy this one has included us in its territory. To get decent photographs of its coat I will need to set up a remote live camera and use radio control on an slr. Done that before to get decent shots of wildlife, well the slr part, so could be a project for September.
Another problem with the distribution records for wildcats and subsequent extrapolations of their numbers into concerns over their future is that they rarely present themselves in the open so sightings are normally brief glimpses and thus many are recorded around areas of high population as probable or doubtful rather than affirmed.
The sightings from 'trusted' observers tend to be rural, as this is the domain of farmers, game keepers, etc. who are more likely to have repeated exposure to sightings.
Rural Scotland is populated very sparsely, so there is no real way of measuring the overall population accurately.
From the number of sightings I have made I would be very surprised if the numbers were as low as suggested.