Looks about 5 1/2 or 6 inch spacing, so much like the MTH Dual engine shed, This topic gives you several ideas on how to get that spacing https://ogrforum.ogaugerr.com/...mth-dual-engine-shed
Example showing 072
Again, based on the picture and this detail from Lionel, I'm guessing, but the 5 1/2 to 6 inch spacing seems right. Lionel lists the dimensions of the tower as 5 1/2" x 5 1/2" x 19 1/2", looking at the picture, if you moved the tower to the right over top of the 2 tracks, I'm again guessing, but it looks like the legs would center over the 2 tracks. Hence a guess, that 5 1/2 might be the near correct number.