Scooterotica

Ok here's my predicament...........
Polini 208 piston disintegrated on way to Cleethorpes earlier this year so bought new kit from Beedspeed.
Fitted new kit and it doesn't run as well as old kit, took head off and found about 1.5mm negative deck.
Piston lines up with ports at BDC so either new barrel is taller or piston is shorter??? (Had this on mates scoot, Sean and Dan dyno'd and sorted squish, mate changed piston and ended up with over 2mm squish!)

Anyhoo, scoot runs ok, it pulls like a train up until 60 (GPS) but then has nothing more to give. I'm presuming it's down to lack of compression/squish as the set up is the same as my old kit.
So I have 2 options as far as I can see it, I either have a bit taken off the top of the barrel ( a mate has the facility to do this,) or I have a head recessed to raise compression and get me somewhere near to a decent squish (but don't know anyone who can carry this out.)

Whichever solution I go for gives me more or less the desired result but which is the better way to go?
If I have the barrel shortened I can't be guaranteed that next time I need a new piston that the height is going to be the same as the one being replaced - I've measured a single ring and 3 twin rings and had .7mm variation between them - which will then require messing about with different head gaskets to get squish correct again, or I go with a recessed head which has the benefits of going back on in the same position each and every time it's taken off, but again if/when I need to get a new piston I'm going to have the same problem with deck variation.
An additional problem, as far as I can see, with the recessed head is that after a rebore the recessed head will have a gap as the barrel is now wider so not only will i require a new piston but also a new head???

I think I've answered my own question really but just want to know which way some of you would go?

either way when you change the piston you can use head/base gaskets to get your desired squish, i suppose if the barrel is easilly done then go down that route tho i would say spigoting the head would be preferable
it might be the cases that are different, i know the 3 smallframe ones i have are, not by much but 0.5mm will f@@k up the squish just by a top end swap but i have them milled and then use packers to get the squish right

Jamey, like I say kid it all lines up at BDC so casings are ok, had exactly the same problem with daves scoot after it being squished by Sean and Dan prior to going to Gibralter last year, he changed the piston and put the squish completely out!

I'm open to suggestions as to which is the best way to go but like I say if I get the head spiggoted and then get a rebore the spigot would no longer be tight in the bore and negate why you had it spiggoted in the first place?

then get the barrel done and if at a later date the piston turns out to be taller you can just fit a thicker base gasket, thus keeping head and squish how you want