I've had a couple of Cota 348's over the years.
Whats the issue with your old lower legs?
I'm thinking they are the square type like the 348 had.
I had a big off at the 1979 Aussie C/ships in Canberra and dented the lower leg that bad it locked the fork solid
On the first lap of the first day
We where able to eventually get the leg apart (well after I'd DNF'd the event) & we had the dent machined out so the fork would work again.
Is that your issue?
Also 248 or 348 Trial had the same fork legs me thinks, so that may expand your searching ability.