Yes sure we can lengthen your straps, Name, Number, Price range, Time frame...
pop them on and we will measure them (you might have to cut them to get them on, or even just so you can get a good measurement)
Note, you're fairly sure this is about normal size for your feet? With people with "puffy" or swollen feet, the size of their foot can change dramatically in just one day.
... lets measure them ... so at the moment it's <insert cm> over your foot on this strap, we can make them fit that 27cm, but sometimes you may find your feet swell more or less at different times.... so if we have to change them again ... you would be looking at additional cost ...
Maybe lengthen with elastic, to allow for some change in size
Decide - cut and add in, or add onto the end?
Before doing anything take a measurement of the existing length, or work out the exact finished length, so you know where you are headed if you loose your way!
Cut and Add in
1 Cut/unpick on an existing seam or cut out of sight, stagger the cut of the lining so that joins are apart by 20mm or so
2 Skive and glue in new strapping
Cut the Strap - One nice straight cut
Add onto end
Where to lengthen
Try for an existing seam, or at the point where the strap attaches to the shoe otherwise add it on the end.
Measuring Straps to lengthen
Measure from two known points on the shoe with a tape measure then you can always check back to those numbers later, works better than “just add about an inch”
Have a thimk about it – the jolly stuff stretches!
Select leather and cut piece to insert
Cut front piece to the exact width using straight edge and knife
Skive ends to fit, think about and buckles or fittings that the strap may have to go through, and how this may effect joins
Glue skived ends together, usually yellow glue
Glue back on and trim
Stitch - note clamp and 3mm Buffalo that has been thinned out to fit under the foot as a guide to give nice straight rows of stitching
Stitch on existing stitch lines where possible, avoid going across the strap unless you feel it's really needed.