Hi,
I don't know if this will help, but if you look at the old maps ( especially the one in 1899 -Glamorganshire 1.2:500 as it's clear without paying for a sub) - and also going by the 1901 census it seems it was between Victoria ave and Victoria crescent.
If you look very carefully at Victoria ave on the os map below, which is near the baths and laundry in Victoria park - on *our right hand side (*facing the screen) the houses on the road have a narrow curved road running between them - it isn't named on the map, I wonder if this could be Hawarden Crescent, or even Victoria crescent . The 1900 map I don't think has the road names on it ( I can't zoom in on it enough to see clearly- I'm not a subscriber) , but what I can see it looks very similar to the 1900 os map that I own, and it doesn't have street names on it.
I would say it is definitely around there somewhere.
The census goes Victoria crescent to Hawarden Crescent to Victoria Ave to St Helen's Crescent (Like Victoria ave, st Helen's crescent is also visible on the os map, but what is missing is Victoria crescent and Hawarden Crescent) I think it may be possible one of these crescents could be that small curved road going through the houses
https://www.old-maps.co.uk/#/Map/265307/192629/12/100633Kind Regards
Ps if searching on ancestry for a Llewellyn Maddox, he is transcribed as
Llewellyn Maddon on their site ( there's an ink blob on the end letter of his name)
