Merry Tiller Extension Tubes

You'll be lucky. I remanufacture them and the tube costs me £50 a 6m length. The OD is 1.635" ID 1.265" 11" long. The holes are 10mm diameter and the one at the rotor shaft end is 1.125" from the end. The hole nearest the other end is 0.75" from the end and there are six alternative holes for the wheels at 1.125" centres.

Ah yes! I spotted those too...... shortly after placing a winning bid on a lot that included front balance and wheel weights, as well as extension tubes, and ratchet wheels (just arrived today  ). I've seen a few on-line comments that the heavy extension tubes are like hens teeth, so I'm amazed there are no bids on these yet - might buy them anyway as a spare, if it stays that way.

Btw, the "tube" looks like 1.25 inch Nominal Bore Schedule 80 pressure pipe to API 5L/ASME/ANSI standards - a bit fancier than the common or garden tube most stockholders carry, in which case I guess £50 for a 6m length is not so surprising - but thank you for posting the dimensions anyway.