It would apply to Hummel, they are the kit manufactuer.
It would apply to Coventry, irrespective of whether Hummel are the manufacturer, or Fred in Brum makes them in his shed, or they buy them direct from a factory overseas. All UK businesses with a turnover greater than £36M, have wider legal obligations and responsibilities under the modern slavery act 2015.
This applies to every business, no matter what they do. You have to put out an annual statement of what steps you are taking in your business to ensure your supply chain is free of slave labour etc. Lots of businesses with turnover of less than the legally required threshold are also declaring and publishing an annual statement.