There doesn't have to be anything nefarious to it, it may well be they were offered based on their size and sales history - not every dealer can sell 60+ cars in a matter of days. And as someone suggested, maybe some dealers have it in their agreement that MG supply them a minimum number of cars, but that's speculation.
Chorley are also a lot more switched on than many dealers I've spoken to that don't even have the initiative to chase their MG contact without being prompted ?

. Chorley, Luscombe's or whomever was given the chance, quite rightly took what was offered and got some income. I certainly wouldn't have said no...my only thought would've been to protect my business & pay my overheads. Someone at MG would have to explain why they didn't use these vehicles to clear waiting SR orders.