Yes. It was originally tangerine when first built, September 1970, but Richard Atkinson painted both of his yellow. The other (the plywood Ford V6) was silver blue. Phil Foulkes now owns that car. Both might have been imported from the UK at the same time and there was some dispute over the actual years of build, but I have a copy of the original build papers so it was corrected on the system.
Both Rod Hemmings and I wanted number 30, (3.0 litre 3000M) so I can understand the confusion! When I restored mine, 1993/94, I had it painted silver and eventually went for number 70 on a permanent basis, which occasionally had to be 170, before transponders allowed the series numbers to be carried permanently. I think the early Hampton Downs Festivals, I had to run with 170 as they were not series rounds and preference was given to others.
The day before my 50th birthday I ran with 149...
As an aside, the GT40 was because it was 40" tall. I think the Marcos is 43" tall, but one's nether regions actually sit below the side chassis rails/sills, by a couple of inches making the seating extremely low - and they would not pass the police "4" from the floor test, as applied to the boy racer cars.