You might be able to find a pair of brackets from another motorcycle that works. Here are a pair of Yamaha IT brackets that fit 38mm forks, and they are short.
http://www.ebay.com/itm/Yamaha-IT175-IT250-IT400-Headlight-Head-light-Mountin...Here is a list of motorcycles that use 38mm forks:
38 Honda CR-125R (81-83)
38 Honda XR-250R (84-85)
38 Kawasaki KX-80R2/R3/R4/R5/R6/R7 (92-97)
38 Kawasaki KX-125 A6-A7 (80-81)
38 Kawasaki KDX-200 A1-A3 (83-85)
38 Kawasaki KX-250 A5-A7 (79-81)
38 Kawasaki KDX-400 A1-A2 (79-80)
38 Kawasaki KX-420 A1-A2 (80-81)
38 Kawasaki KL-600A1 “KLR” (84)
38 Kawasaki ZX-600C1-C6 “Ninja” (88-93)
38 Kawasaki ZX-600C7-C10 “Ninja 600R” (94-97)
38 Kawasaki KL-650A1-A18 “KLR650″ (87-04)
38 Kawasaki VN-700A1 “Vulcan” (85)
38 Kawasaki VN-750A2-A20 “Vulcan” (86-04)
38 Kawasaki ZX-750F1-F4 “Ninja” (87-90)
38 Kawasaki ZL-900A1/A2 “Eliminator” (85-86)
38 Kawasaki ZX-900A1-A3 “Ninja” (84-86)
38 Kawasaki KZ-1000C1-C4 “Police” (78-81)
38 Kawasaki KZ-1000J1-J3 (81-83)
38 Kawasaki KZ-1000K1/K2 “Ltd” (81-82)
38 Kawasaki KZ-1000P1-P20 “Police” (82-01)
38 Kawasaki ZL-1000A1 (87)
38 Kawasaki KZ-1100A1-A3 (81-83)
38 Kawasaki KZ-1100B1/B2 “GP” (81-82)
38 Kawasaki KZ-1100D1/D2 “Spectre” (82-83)
38 Kawasaki ZN-1100B1/B2 “Ltd” (84-85)
38 Suzuki RM-125 N/T/X/Z (79-82)
38 Suzuki RM-125 D (83)
38 Suzuki PE-175 Z/D/E (82-84)
38 Suzuki RM-250 N/T/X/Z (79-82)
38 Suzuki RM-400N/T (79-80)
38 Suzuki LS-650 FG/PG/FH/PH/PJ (86-88 )
38 Suzuki LS-650 PS/PT/PV/PW/PX/PY/PK1/PK2/PK3 “Savage”
(95-03)
38 Yamaha YZ-125 H/J/K (81-83)
38 Yamaha IT-175 J (82)
38 Yamaha IT-175 K (83)
38 Yamaha IT-250 H/J (81-82)
38 Yamaha YZ-250 D/E/F/G (77-80)
38 Yamaha FZR-400 U/SUC/W/SWC (88-89)
38 Yamaha FZR-400 A/SAC (90)
38 Yamaha YZ-400 D/E/F (77-79)
38 Yamaha IT-465 H (81)
38 Yamaha IT-465 J (82)
38 Yamaha YZ-465 G (80)
38 Yamaha XT-550 J/K (82-83)
38 Yamaha FZR-600 W/WC/AC/B/BC (89-91)
38 Yamaha FZR-600 RA/RAC/RB/***/RD/RDC/RE/REC (90-93)
38 Yamaha FZR-600 RF/RFC/RG/RGC/RH/RHC/RJ/RJC (94-97)
38 Yamaha XJ-600 SD/SDC/SE/SEC/SF/SFC/SG/SGC “Seca II” (92-96)
38 Yamaha XJ-600 SH/SHC/SJ/SJC “Seca II” (96-97)
38 Yamaha FZX-700S/SC/T/TC (86-87)
38 Yamaha XJ-700N/NC/S/SC “Maxim” (85-86)
38 Yamaha XJ-700 XN/XNC/XS/XSC “Maxim” (85-86)
38 Yamaha XV-700L/LC/N/NC “Virago” (84-85)
38 Yamaha XV-700CS/CSC/CT/CTC “Virago” (86-87)
38 Yamaha XV-700 J1/J1C (97)
38 Yamaha XV-750 U/UC/W/WC/A/AC/B/BC “Virago” (88-91)
38 Yamaha XV-750 D/DC/E/EC/F/FC/G/GC/H1/H1C/J1/J1C “Virago”
(92-97)
38 Yamaha XV-1000 L/LC/N/NC “Virago” (84-85)
38 Yamaha XV-1100 S/SC/T/TC/U/UC “Virago” (86-88 )
38 Yamaha XV-1100 W/WC/A/AC/B/BC/D/DC/E/EC “Virago” (89-93)
38 Yamaha XV-1100 F/FC/G/GC/H/HC/J/JC “Virago” (94-97)