It’s documented that (2) AC factory cars were prepared with FIA suitcase "dimples" (See Photos). The second modification was to enlarge the trunk base to allow the suitcase to fit upright (vertical) and further down into the trunk as shown. If you look closely at the photo (I have the full size), you can see the suitcase also fit horizontal and was held in place with a “bungee cord”. You can also see the bolts protruding out the bottom of the suitcase which originally held the suitcase upright. I think this also explains why some of the FIA cars had dimples while others didn’t.
As for the actual size of the suitcase – I have a copy of the original – “FIA Historic Racing Championships - Appendix J” both 1964 and 1965.
They state the following:
“270 - Luggage trunk
A covered space being an integral part of the coachwork but outside of the space occupied by the front seats, large enough to receive a trunk of
65 cm X 40 cm X 20 cm. minimum, besides the spare wheel, tools or the folded hood, shall be provided, excluding the spare wheel, tools or removed canopy.”
Hope this was helpful.
