Took me a bit longer than planned to get back to you - hope I can help! The Cotic Soda is one purty frame - please pop up some pics when you're done with the build! The brown B17 Special is now sitting on the old frame, converted to a singlespeed... The Swift is now on the old-new softail. Regarding the width issue - it unfortunately might be something you would have to keep in mind... but I don't necessarily think it has to be an insurmountable obstacle... Straight off the bat - I'm probably the most un-supple specimen to ever throw his leg over a bicycle... I have manhole covers for hamstrings, and think I skipped that part of my development in the womb, when I was supposed to get elastic-y joints. Think lego-man. I apologise if I'm belabouring this point, but I feel it necessary, since I seriously doubt that anyone who is moderately supple will necessarily battle like I did initially... It took some major getting used to when I first started riding with the B17 Special - but keep in mind that it's a whopping 175mm across at the back... I don't have particularly long legs, and did I mention I'm as supple as an ironing-board(?), so it was a bit hair-raising the first time I took a drop-off, and realised I couldn't slip over the back of the saddle like I used to... It definitely required a change to my riding style, and I needed to keep the extra time it took to get off the back, in mind when picking lines and planning ahead... With this being said - I kind of managed a half-off-the-back stance if I needed to make the adjustment quickly, but things sometimes got tricky, particularly with the baggies occasionally hooking on the two saddle-bag loops/eyelets that you find on the back of the Brooks saddles... Despite the above, the relatively few times per ride that I needed to pop off the back, compared to the many km's spent sitting on the saddle, in absolute comfort, saw me readily overlooking any minor inconvenience. Bottom line is, you can adapt your stance, and get around it... Regarding the Swift - at 25mm narrower (160mm) than the Special - the difference was major. I can slip off the back with little to no problems on the Swift, when compared to the Special. I would be inclined to say that the same should apply to you, but of course - the major difference is that I'm coming from a 175mm down to a 150mm - whereas you would be going from a 143mm up to a 150mm... But then again - it's only 7mm in difference, and when you add in that a well-worn-in, and cared-for leather saddle, will actually become smoother with the passing of time, I seriously doubt it will be very problematic... I'm obviously quite biased towards these saddles... I think they can be comfortable as hell - and don't get me started on the craftsmanship, and that if you look after it, you'll never need a new saddle... Weight issues aside, the only other reason why one might not consider them, would possibly be due to the width - but in your case, they are so close, I don't see it being a factor... Hope this settles any queries!