the following should work:
unld "svtvme_th.o"
ld < svtvme_th.o
you have to use svtvme_th not svtvme_fer

svtvme_th is the complete module, the other is only a part and
has not been compiled/linked in the proper way. Or I think this
is the explanation...

you should see something like this:

tstsvt1-> pwd
b0dap24:~belforte/svtvme_fix/lib/VxWorks-5.3/ppc
value = 49 = 0x31 = '1'
tstsvt1-> unld "svtvme_th.o"
value = 0 = 0x0
tstsvt1-> ld < svtvme_th.o
Undefined symbol: gzopen (binding 1 type 0)
Undefined symbol: gzread (binding 1 type 0)
Undefined symbol: gzclose (binding 1 type 0)
value = 129314184 = 0x7b52d88
tstsvt1->