Hi toby1,
What is comfortable and fast for me, may not be for you. Keeping that in mind, I will tell you what I would try first. Also, what key is this in?
For the Bb chord on the first beat I would use 1235. I'm assuming that Bb is in the key signature here.
Beat 2 I would use 23 for the df holding 3 on the f and repeat the d with my second finger. So, the bottom voice is 2212 while holding the f with 3.
Now come the 5 ascending 6ths. The a flat in the next measure makes me think that the e's are flat in the ascending 6ths. I play 6ths with either 13,14,15 or 25. So, here I would first try to use one hand fingering for all the 6ths. If the B's and E's are natural then 15 would probably be comfortable.
If the B's and E's are flat I would play the first DBb 6th 15 then switch to 14 for the repeat. This sets up the EbC to be fingered 25. FD with 14. GEb with 13. AbF with 14 (or 15 if you prefer that).
This might work for some people, Joe.
Topic: How would you finger this?