my understanding is that the L250 was made in a variety of woods, whereas the 250Ti was ONLY made in teak
I have used a beeswax wax on them with great results...the beeswax contained a citrus cleaner and is applied with a very fine steelwool. that cleans the dirt out of the pores and replaces with the wax.
I think the marks you are referring to are missing veneer around the skirt ?? we all have that problem...there is a good thread around here just about that topic...I used a walnut stain that darkened the areas and are now almost invisible...sliding them around on rug seems to cause this ..... get some decent feet under them...also a thread about this ....just search on "250ti"
here's some links to get started:
http://www.audioheritage.org/vbullet...ighlight=250ti
http://www.audioheritage.org/vbullet...hlight=beeswax