Iceberg block is from Mr Eales - who develped the 4.2 for Landrover, and later the 4.5 for the original Dakar racers.
He has a few stashed in his workshop.
His 5.2 engine is legend - I put one in my TVR Griffith - still going strong.
He still has his road car(1990 RRC) with all the dakar bits and the 4.5. which Damon Oorloff at Kingsley Cars will be restoring for him soon.
I would think that unit cost 7500 plus VAT.
My friend Colin has just bought a brand new 4.6 from Mr Eales with the same cam as the video, internally balanced, for 2600 including VAT and delivery
he will bolt on a pair of nice rebuilt heads from a 4.5 chimaera, freeflow ashley headers and hey presto - 280bhp and over 300lbs torque in his 50th anniversary defender - lovely.