Need 90mm Colorplan Leitz lens

For the Pradovit color my son recently acquired,
the lens barrel is present, but there's no glass in it!
This lens unit has the plain mental hood (rather than the black hood)
and had a barrel of a slightly larger diameter than the one with
the black hood.

Anyone know of the avaiability of such lens?

My son is selling the projecter once he finds the lens.

TIA,

Collin