problem: package for new font

Dear Friends of Metafont,

I'm trying to define a package desalph.sty, on the model of tipa.sty,
to facilitate use of my desalph font for the Deseret Alphabet, just as
tipa.sty facilitates use of the TIPA (IPA) fonts.   Typically
my documents will need to include both packages:

\usepackage{tipa}
\usepackage{desalph}

The desalph font itself (METAFONT) seems OK.  I can view the proofs and 
I generate
(currently) 12pt and 24pt sizes.  The Deseret Alphabet is a phonemic
alphabet (for English) so I defined an encoding called LDA which is
based as closely as possible on the T3 encoding used for tipa; this
allows me to use much the same entry shortcuts for both.  I have defined

	desalph.sty                       (defines  \textda{.....} and 
environment da for Deseret Alphabet)
	ldaenc.def                         (defines the LDA encoding)
	ldadesalph.fd

********
I also have a file
	ldacmr.fd       but do I need this?

*********

I'm doing something(s) wrong.  When I try to run the following document
(in TeXShop 1.28 on Mac OS X 10.2.4)

\documentclass[12pt,a4paper]{article}
\usepackage{tracefnt}
\usepackage{xspace}
%\usepackage[T1]{fontenc}
\usepackage{times}
\usepackage{desalph}
\usepackage{tipa}

\title{This is the Title}
\author{Kenneth R. Beesley}
\date{29 March 2003}

\begin{document}
\maketitle

Here is a test of simple roman text.

Here is a test  of the TIPA package \begin{IPA}DIs iZ @ tEst\end{IPA}.

This is a test of the desalph font \begin{da}dEzirEt 
\ae{}lf\ae{}bEt\end{da} package.

Another test \textda{hw6t Iz D pr6blEm} with this font?

\end{document}

TeXShop/pdflatex happily loads article.cls, size12.clo, tracefnt.sty, 
xspace.sty,
times.sty, and then (of course) has problems with desalph.sty.

******
First it loads fontenc.sty, because desalph.sty has a line

\usepackage[LDA,\f@encoding]{fontenc}

to cause ldaenc.def to be loaded.
Question:  Is this the right way to cause ldaenc.def to be loaded?

******
Then ldaenc.def gets loaded, then ot1enc.def.  And I get a message

LaTeX Font Info:  Redeclaring font encoding OT1 on inputline 38
))))
!Missing = inserted for \ifnum.
<to be read again>
         -
l.8 \usepackage
                {tipa}
?

The TeXShop test-consol interface then stops and asks for Tex Input.  
If I enter a newline, the
processing continues, loading tipa.sty--- and my document, including 
the desired Deseret Alphabet
text,  actually gets generated.   So I'm almost there.

If anyone could clarify the "Redeclaring font encoding OT1" and 
"Missing = for \ifnum"
messages and help me load the font encoding(s) correctly, I would be 
most grateful.

Ken Beesley