I had the same idea regarding the steering column.
It is surprizing how far off-set the standard triumph steering column is.
I had the added problem of the BMW exhaust manifold to get passed
I think I ended up using the top part of the Triumph column and the lower part of the BMW column which left a U/J in the centre. This just passed under the exhaust manifold with mm's to clear.
I'll get a few photos in the morning.