11.5'' Stoneware Lampbase - Impressed mark

Hi

I've had this one a while and every time I look at that mark I see something different. I got round to taking the felt off of the vase rim today but nothing extra.

This said for a while I'd thought it could have been the cross in the Lowerdown Pottery with the L obscured... not sure on that one now.

Looks almost like a large letter T sometimes, doesn't look MDT though. There's a round paper label residue on the front base that I've left but may not be original.

I thought perhaps the form and finish might be known to someone here and we could then look backwards from there to identify the mark.

Thanks