It is indeed well made, going by the photos. If its a Dapol kit, it must be a fairly early one as the one I tried to use for a similar exercise was made that flash-ridden cheap grey stuff that is distorted due to the tooling deteriorating with age. I gave up after a while.
If I wanted a Deltic prototype, I'd grit my teeth and get either a Bachmann one or the Hornby "collectors" version.