_Firstly what type of tool are you using which shows up the errors in site code? I would like to check the site myself for these errors. _
I have been a coder since 1993 before most browser lol. I look at everything with my own eyes and just see it immediately.
_It would be maybe a lot of work to change the entire site in one go etc. _
Nothing wrong with doing it bit by bit. Google algorithms will however take a look at the site as a whole for additional ranking signals, so I would look at extracting that data and dropping it into a new template at some point. It is also very confusing for a customer to land on that page only to click on a link and have a totally new site layout.
Do you think initially it will be a good idea to get a coder to just look at the old site and fix any errors?
Yes the errors will likely all be the same or similar and should not take long to fix.
From customer feedback they seem to think it looks okay for the products old cottages
That is always a good sign, however that may be a very specific audience and you might be missing out on a much larger audience who may hold less trust in a site that looks dated compared to other sites. Its all about first impressions.
_I have run a test _
Plenty of tools out there to look at things however they wont reveal too much detail just the standard things its looking for that most people get wrong. I assure you that the coding issues you have that need fixing are not the same as others. Even down to the broken google plus code you have in the top left corner. They will be pretty unique to your site.
