[PROJ] legacy problem building v5.2.0 on Windows10

[Wells, Roger K.]

We have been using proj for a long time and are now in the process of
moving up to the newer releases.
The host OS is Windows 10, up to date & build environment is
msys2/mingw64 up to date as of January.

I still need access to the now deprecated api's: pj_init, pj_fwd, etc 
for a while.
A few months ago I pulled this off with v5.2.0, v6.3.2 & maybe v7.?.?.
Now, when I build v5.2.0 I do not have access to those api's. (the dll's
I built in January do though)
and I simply can't remember what I did other than execute ./configure &
make after un-tarring the distribution file.
Any hints will be very much appreciated.
thanks

-- 
Roger Wells, P.E.
leidos
221 Third St
Newport, RI 02840
401-847-4210 (voice)
401-849-1585 (fax)
roger.k.wells at leidos.com