This page provides information about modelling the railway and tips and advice.
Unless you're dealing with ancient history line side fencing is covered by Section 64 of the Railway Clauses (Consolidation) Act 1845. As its title suggests this Act basically brought together best practice from previous ones and thereafter any new railway works had to be carried out in accordance with its provisions rather than re-inventing everything each time.
So far as line side fencing goes, (which was indeed primarily to prevent railwaymen straying on to adjacent land), the standard applied at least until the 1970s was 1.4 metre high post and rail (two rails) or five strands of wire.
As you can see from the photograph this does not seem to be the case here. New concrete posts with 4 strands of wire as the main divider between the railway and Hop garden. This photograph is 1961 so I assume this is recent fencing. The short fences to protect the ungated crossing only has 3 wires visible (you can see 4 on the other side). I am assuming 4 inch square main posts (scale 2.3mm) with 3 inch square bracing and intermediate posts (scale 1.8mm) and about 4 feet from ground level (scale 28mm). I am assuming 15g wire (1.8mm) at a scale gauge 46AWG or 0.04mm
Reference: Railways Clauses Consolidation Act 1845
Starting to put together materials for the buildings. The station buildings are corrugated iron so finding a supply of this is important. Interesting article on RM Web about corrugated iron required for Colonel Stephenson's 7mm project here.
Interesting dimensions identified in this specific post
Also a piece on Wikipedia that discusses corrugated iron and the different types used on roofs and walls. It was once common for CGI used for vertical walls to have a shorter pitch and depth than roofing CGI. This shorter pitched material was sometimes called "rippled" instead of "corrugated".