Hi Nigel, I'm not sure about that specific part number, but I can confirm that the Fiat Bravo back box does fit the Delta as the floor pans are identical.
Hi Penguin - Got a bit of a result - I cross referenced part numbers on eper again. I have found that part No.51816909 - sold on ebay to fit the T-Jet Bravo appears to be exactly the same as the MultiAir rear box. You can add any FCA group part number to eper and can select the 'Product Previously in Use' drop down - and will show commonly used other models across the marques. I've bought a brand new aftermarket one sold for the Bravo off ebay for £30!!!!!! It looks identical. I've not actually got around to fitting yet as the EML light has now gone off - the hole is only small and the Lambda/ECU have obviously adjusted - though we're away to Devon in a couple of weeks so will fit before then and confirm. The local Chrysler/Jeep dealer wanted £185 for want effectively is the same part!!