G'day just having a look at this thread and the photo and to add a few observations,
With the wide seat back he must have been a big boy and added the extra down tubes to the inside to help protect his hips and elbows from the wheels.
The other forward support tubes from the strut plates are stock series 1 and 2.
Throttles are early stock type.
The extra fuel tank looks like it was still being set up. clamped in place with no visible bolt holes or fuel line atttachments.
The seat seems to be the more upright type for the larger fuel tank.no visible rivets about six inches behind the seat attach bracket were it may have been originally fitted with the early 5 litre tank.
The seat support tube that runs from the strut attach points and under the front of the seat is underneath the foreward tubes and along with the straight stick indicates that this is a early 2 with pioneers. and possibly not a modified series one it will have the 016 skins on the leading edge.
Another indication of stock 2 or an updated 1 would be the ruddervators. if they are stock then the cross brace tube between the l/edge and trailing edge will be in the centre. If it was modified to the shorter tail it will not be in the centre.
Best thing about this bird is that it is straight. Other than the new control rods that will take all of 30 minutes to make and fit.. just covering and if the engines have been stored well maybe a couple of carb kits from heeters.com and he's away.
good score, go for it.
ozzie update.
have only logged an hour so far this year. Summer weather was pretty wild and unpredicable. (33,000ft is the new altitude record for a paraglider) Now Autum is here it has settled right down, in fact the last 3 weeks have been perfect no wind and light thermals right across the southern states. Of course i was travelling on a work trip. talk about peeved. Now that i am home it has started to rain. The real stuff that is actually filling dams and farmers fields (at long last). I'll gladly sit on the ground as long as it keeps raining inland. i'll keep using the time to continue with some small details with my Lazair along with a few personal touches for comfort ect and still continuing research on going electric. Battery weight is the real hold up here not to mention the cost for two engines. but there are some interesting advances in electric flight happening. see what the future brings.
Enjoy your upcoming flying season and summer. I just had a heap of firewood delivered, at least i won't have to fight my way thru snow drifts to get to it
OZZIE