Bytea to Text problems

I've searched high and low, and all I've found is people being chided
for trying to convert from Bytea to text :)

When I first designed my database, I simply didn't understand the
purpose of bytea, I didn't actually realize that there *was* a text data
type.  (Actually, I was porting from a MS SQL database, and if I
remember correctly, PgAdmin actually made the decision for me)  I now
need to convert my field from bytea to text, but there doesn't seem to
be a clean way to do it.  So far I have done the following:

alter table tbl_inventory ADD longdescription_new text;

update tbl_inventory SET longdescription_new = encode(longdescription,
'escape');

update tbl_inventory SET longdescription_new =
replace(longdescription_new, '\256', '\n') WHERE longdescription_new
LIKE '%\256%';

(ad infinitum)

The problem is that encode, obviously, escapes a metric ton of stuff,
and I have no idea *what* is being encoded, or even what it is being
encoded into, other than exhaustively digging through my data and
comparing the escape codes to the original text.  Is there a chart
somewhere that will show me?  Is there a script that will do this?

John