Evening Mollie. 
Yes, to mark out the area she wants covering with 4cm thick fake grass i made up 4 pieces of sttring with loops to go over 4 steel tent spikes, that was for a 4 x 4m area but now its going to be 4 x 3.
She has ordered a training bike, she says she hopes i'll be able to build it, never found anything i couldn't build.
The shortbread recipe was this, 4 oz butter, 2 oz caster sugar and 6 oz flour, that was it, the grams were 125g, 55g 180g plain flour, so it had to be too much flour or not enough butter.
Yes, as you say, only the brown bread was sinking, i only went as far as 50/50 so never made full wholemeal, i assumed that for the loaf to sink it must have had air which disapated during baking.
I saw this when i asked google the question.
[During baking, the loaf collapses. Oven temperature that's too low. This means the dough rises to its maximum, then collapses before it gets hot enough to set. Or, dough could have been over-risen]
Been watching mainly recordings, the only thing thats live is the dreadful, news.
Watching, 8 out of 10 cqats does countdown.
Have a good night, sleep tight.