Jonathan, I think it may of been taken at Combe farm next door to Port Lympne which they also own going by the look of the indoors of the barn, It maybe Torgamba
That's definately Torgamba at Port Lympne. From the large size of his horns I would say it is in his latter years at the park, so taken indoors in the rhino house(?). If you look at the Rhino Resurce centre sumatran rhino photos, there are some of him taken in the Combe Farm accomodation- a stableyard- shortly after he arrived. You can see how much smaller his horns are then.
What I've not been able to find out is how these big horns became tiny again after he went back to Way Kambas !- were they sawn off to prevent damage in transit, or to prevent him being an irresistable target for poachers, or was it natural wear and erosion in a natural environment(I find the third option hard to believe). Nowadays he has only small bumps like the other rhinos there...