I live near track, to my knowledge they don't "assemble" anything, they are just a retail outfit specializing in ML gear. The don't have a
"Track of the Wolf Lock"
They always state what maker's parts are offered in their kit's but you have the option of getting whatever you want.
They are primarily a mail order supplier, they do have a small walk in show room, perhaps 16'x16' open limited weekday hours for us locals and anyone traveling through, but you flip through the catalog and point to what you want,,then they go back and get it.
Neat thing is you can handle some of the fine arms they have for sale, some real buet's!