Not worked on an H22 heads myself, but this is the exact one I've used on various engines before now (OHC and push-rod)
http://www.ebay.co.uk/itm/vintage-sykes ... _22wt_1255
There's several of those on ebay atm, that's the cheapest but there are ones ending in a day at £25 with no bids. I have no idea why he's described it as 'vintage', because it isn't that old!

If I could find the damn thing, I'd offer to lend mine to you, but I've looked twice recently and can't locate it
EDIT: This one looks exactly the same type but with more adjustment, so should be a safer bet (and even cheaper too!

)
http://www.ebay.co.uk/itm/SYKES-PICKAVA ... _25wt_1255