I don't know for sure but if the low line was a 4/4 with plus 4 wings and wheels I would have thought it would have been the narrower 4/4 chassis as the wider plus 8 chassis was used on the plus 4 and plus 8 in the 90s and it wasn't until around 2004/5 that the same chassis, and therefore tub width was used. I have one of the last narrow bodied 4/4s and it's definitely cosier than a plus 4 of the same vintage.
