with warm up and cool down those workout days would be 10.5-11.5 km, medium days are already 10-11 and could gradually build up to 13-14 (that was the plan anyway) and long run could just keep building bit by bit toward 42 until the 50k at end of october. that would mean weekly mileage starting around 70kpw and going up to 100kpw, give or take. and do weights on one of the easy weekdays in addition to the saturday.
ultra people talk about the importance of back-to-back long days but i feel like if i build up to a full marathon long run before the 50k, race the 50k, and then taper down to the 50 miler, that should be plenty. finishing 50 miles just doesn't seem that daunting. and wouldn't getting up at 6 AM to do a 3x10 less than 24 hours after finishing a long run serve the same purpose, pretty much?
I suspect your workout days would be longer, mine are like 10-10.5k and you're faster than me.
Also, I imagine wouldn't really be straying too far from the core concept if you changed i up to 2 x sessions + back-to-back long runs for a special block for your ultra.
