Have you considered James Parrott Harriss (birth reg Jun qtr 1870 Islington) who in 1891 as James P Harriss, 20, carman, b Islington, was with parents James T and Annie E in Clerkenwell - in the parish of St Silas Pentonville which was where Beatrice had baptised two Neal children and where James and Beatrice were in 1901?
His 1891 occupation of carman also fits with the James Harriss, removal carman, in 1901.
1891 ref: RG12/226/102/7.
1881 ref: RG11/236/17/28. (Harris)
1871 ref: RG10/257/59/46. (Harris)
The family is unfortunately not in Holloway in the censuses but the Hornsey Rise birthplaces shown in 1881 for children Ann (6) and John (4) suggest they were up that way for a while at least.