Another funny root

The acrostatic (Narten) root *te:k^T- (< *te:tk^-?) 'to fashion, create'
also looks like a reduplicated formation. Perhaps it originally
patterned with the "ordinary" athematic type of reduplicated presents,
as represented by *dHi-dHéh1-ti/*dHé-dHh1-n.ti 'put'. The original forms
would have been *ti-ték^-ti/*té-tk^-n.ti. When the latter had changed
into *ték^T-n.ti in part of IE, paradigmatic coherence was lost and then
restored by reanalysing the verb as acrostatic, with the analogical sg.
*te:k^T-ti. A related thematic stem may underlie Gk. tíkto: <
*tí-tk^-e/o- 'bring forth, engender'.

The explanation above differs from that of Lubotsky, who assumes some
kind of compensatory lengthening replacing reduplication. If that should
be the case, I don't see why _both_ the "thorny" cluster _and_ the
lengthened vowel should have survived. One would expect *tetk^- >
*te:k^- instead.

Piotr