Since you're into DIY, I would recommend the Seventh Circle Audio N72. https://seventhcircleaudio.com/products/N72 Michael Wagener (King's X, Ozzy) uses the N72 on inside kick drum (along with a Shure Beta 91). (For overheads, he uses the more expensive Neve clones by Great River.) He also uses the Seventh Circle A12 (based on the API 512) on toms. The A12 and A12b have been discontinued along with the 8-channel rack they used to sell. Now it's a small "one-shot" enclosure. If you're still looking for a Neve 1073 clone, I'd jump on the Seventh Circle before it's discontinued. (They've discontinued most of their stuff, including the API clones and 2025 opamp.) As an aside, Wagener's not on a budget as far as gear is concerned. His rack of preamps includes GML, Chandler, Hardy, Great River, API, Summit, Crane Song, etc., and to his ear, after hearing the Seventh Circle N72, there was no reason to drop $4k on a 1073.
As far as the BLA B173 and Hairball Lola, I have no experience with either, but from Hairball's description, the Lola borrows circuit design from John Hardy and John La Grou (Millennia), which means a very neutral or transparent sound. As such, I wouldn't expect their output transformer to make it sound like a Neve 1073, but it should add some girth or character.