Have been looking for a pair of the bottom plates to retrofit onto 280 transom plates
However a little scarce
Have 2 sets of 280 plates one new and one used
was thinking of welding extension on to the 280 plate
Not sure how this would go, however imagine if its all welded, and level and flat on base should be all good to go ?
Has anyone done this before
Im in Australia so some times we need to improvise, as we not spoiled
f​​​​​​or choice like you chaps

I have a friend that has welded extensions and it has worked great for him. He did weld gussets/ribs on the top of the plates and ran them to the tips. Cleaned them up pretty good and painted. He used a 1/2" piece of flat stock, cutoff the tail of the tab off to where the taper was 1/2", heated both pieces on the grill to about 350°F, clamped them to the table and then welded them top and bottom. Do not induce a lot of extra "weld heat", be patient and take some breaks in between to no warp the tab. I'll see if I can get a pic.

I've been looking for 380's also and there are a couple of guys on here that do have just plates only. I've been kicking around welding extension, but probably will just buy new.