Yep. views in RDBMS are much underrated, IMO just because they are old tech. It should be possible to use views to:

1) normalise the database (fold these ugly add-on tables as columns in the parent table, with suitable null constraints, then drop the add-on table).

2) Use views to add the add-on tables (now views) back in again.

3) Continue running the old application code against the views, which present the old, ugly schema.

4) Simultaneously write the new code against the normalised core tables.