Once your mums on the mend he may consider this. It's a Triumph, and although a 750, they are very light (I've owned two, but not leccy start) and its a leccy start

http://www.ebay.co.uk/itm/1982-TRIUMPH-Bonneville-T140ES-Electric-Start-V5C-Factory-Show-Model-VGC-/311689453020?hash=item4892239ddc:g:WwQAAOSwxg5Xyb~0

near mint 3ta 1958 starts first kick hot or cold and often shown in events and all original panels frame and engine match numbers also fully rebuilt engine and sweet as

£p.o.a