What we have here is a gothic revival church where the former sanctuary was essentially closed off. The tabernacle was then placed in front of this on a very rudimentary (and primitivistically decorated) stand with the new altar brought forward into the nave on an eight sided predella. (Clearly there was an attempt -- a sight not uncommonly seen unfortunately -- to make a non-church in the round try to be like a church in the round. In all the examples I have seen of this, I have yet to see an example where this has not been a mistake.)
In the after photograph one can clearly see how something closer to the original sanctuary arrangement has been restored -- and to great effect.
Not only has additional seating been regained in the nave, more importantly, I would suggest that the altar actually has a greater, more intuitive iconic centrality. I would attribute this to a few factors, including the form of the altar, its greater height (by means of both the predella and the reredos) and its harmony with the rest of the architecture.
The church now also benefits from being less dark than in the previous arrangement which is also a help.
For those interested, here is a closer view of that altar -- which is quite dignified with its carvings, dark stained wood, gold leafing and rich colours:
Incidentally, we were only just recently talking about the use of ironwork in churches. Here is another example of such, coming from within the context of this church's baptistery:
(All photos courtesy of Fr. Finigan)