Strictly speaking this is more a kit-bash than a conversion.
It covers the tribal warriors and mercenaries of the 16th to 19th centuries.
For those using that ruleset, the Irregular Wars Arab army list includes civic spearmen, for which figures made straight from the GB set should probably work fine.
The recipe:
Take one box of GB Arab infantry and one box of either Perry or WA Afghans. Take suitable sword-wielding arms and shields from the Afghan sprues and attach them to the Arab bodies.
Only use swords, not Khyber knives, which are peculiar to the NWF.
Only one of the four dynamic, swordsman-appropriate Arab bodies has two separate arms (the fifth pose is static with both feet firmly planted on the ground, body angled for shooting, so it's best used for archers/musketeers). The other three poses incorporate the left arm, and the sleeve reaches to the wrist, so any Perry/WA right arm would have to match. Pairs of arms with shorter sleeves can be used on the armless GB body.
The cascara sword from the GB set can still be used, too; the Arabs used a variety of patterns.
You can also use Afghan heads wearing the more restrained, close-fitting turbans on your Arabs for greater variety.
The WA Afghan set contains more shields than the Perry set: enough to make four of the five figures on a sprue into swordsmen; i.e. 32 figures out of 40 in total, whereas the Perry set contains only 28 for 36 bodies. The Perry Khyber knife arms could be combined with a left arm carrying a musket/jezail. Either way there will still be enough firearms and suitable arms to turn all the figures into musket/riflemen. If you buy both brands of Afghan there'll be plenty of parts to cover all eventualities.
I would think most people collecting Afghans/Pathans will need more than one box, so if you don't want the leftover parts they should be quite sellable.
Another option for the Perry bodies with angarkas(robes) reaching below the knee is to turn them into Baluchi mercenaries, either with sword and shield or jezail (converted to matchlock, if you want greater historical, if not ballistic, accuracy). Then it's just a matter of using the Afghan heads with the bulkiest turbans, and adding long flowing hair and big bushy beards with Greenstuff. The rest is down to the painting.
Of course, you'll be left with loads of GB circular wooden shields and spear-wielding right arms, which will be useful if you or someone you know does enemies of Late Romans or Dark Ages. The shield is the same as the one supplied with the GB DA and Goth sets, and the leftover spear arms can be used to add additional variety to the GB sets or possibly WA Goths.
scratchbuilds another Victorian flying machine.
