Due to my weird dimensions being transferred to my bikes, I’m struggling to get a small/medium seatpack to fit on one of them (OK, with hindsight the seat post integrated rear dynamo light wasn’t the best idea)

Any recommendations for someone who does custom waterproof packs? Might get a frame pack or handlebar bag as well.

Try here

https://www.straightcutdesign.com/

Second what Onion says. Get on touch with Ross at Straight Cut.

Thanks, I’ll try there

Check out Camel Chops, based on Scotland and will make you anything you need in a huge range of colour, patterns or even supplied fabric. Can’t recommend them highly enough.

I have two Alpkit Stingray custom framebags here. Very please with both of them.