Group->parse_model: extend single-carriage special case to BR 640, 650

	my @likelihood = reverse sort { $ml{$a} <=> $ml{$b} } keys %ml;

	# Less than two carriages are generally inconclusive.

	# Exception: BR 631 (Link I) only has a single carriage

	# Exceptions: BR 631 (Link I), 640 (LINT 27, 650 (RS1)

	# only have a single carriage

	if (

		$ml{ $likelihood[0] } < 2

		and not($likelihood[0] eq '631'

		and not(

			(

				   $likelihood[0] eq '631'

				or $likelihood[0] eq '640'

				or $likelihood[0] eq '650'

			)

			and @carriages == 1

			and substr( $carriages[0]->uic_id, 0, 2 ) eq '95' )

			and substr( $carriages[0]->uic_id, 0, 2 ) eq '95'

		)

	  )

	{

		$self->{subtype} = undef;