Yard Butler sells a replacement swivel for lawn carts. I purchased 1 from them back in '14, good quality part.
If all else fails, go to Yard Butler web site.
I have a Backyard Buddy lift which is not bolted down. I have had the lift for about 10 years, have the caster kit, and have moved the lift 3 or 4 times.
Never a problem with the lift scooting out of position from not being bolted down.
Bought 2 jugs from Walmart, sent in the rebate form, and got my check for $24.00 in about 2 months. Make sure you keep a copy of the receipt and the rebate form in case there is a problem.
I'm in southwest OH, and I have a propane furnace with air conditioning for the summer if it gets too hot. My garage is 30'x40' with 12' ceilings. In the winter I keep the temp at 43 and if I'm inside working I boost it up to 65 deg.
When I use the air-conditioner in the summer the setting...
Try blocking off part of the air inlet, use a piece of metal and slowly slide it over the inlet, you should hear the blower speed increase as the static pressure changes