On the finance side - I would expect the loan value to be no more than 60% of the EQUITY in the secured property. Sounds like a slight technicality, but in actual fact a huge difference.
If you try and use a property which has just been purchased with a 100% mortgage (unlikely I know) they will laugh you out of the branch. It is your equity they are after. Property value is almost incidental.
Also, as mentioned earlier, Nat West are by no means a market leader. Anyone will offer you a secured loan with enough security even today. A 'taylored loan' is management speak for 'it depends how rich your mum and dad are'.
These open days are good - but you do need to go armed with some industrial strength gloss remover to get the most out of them.