Longmuir's proposals suggested that the two leagues themselves could be reunited if the SFL clubs please the SPL by accepting Rangers into the First Division, but that looks a vague offer by the SPL, hastily made, uncertain ever to be fulfilled.
Wadsworth believes Gretna will face a struggle to get up and running in time to feature in next season's SFL.
"Sadly, only one Scottish football body has offered us any help or assistance – the SFL – and I would like to thank David Longmuir, Jim Ballantyne and 29 of their 30 member clubs for inviting us into the SFL.
"It was agreed that the SPL would work with the Scottish FA, SFL and Rangers to facilitate Rangers FC taking their place in SFL Division 3 this season," the SPL said in a statement.
But the 27 SFL chairmen eligible to vote turned down the obvious financial benefits to instead welcome Gretna back to Scottish football for the first time since 1947.
The SPL and SFL chief executives, Neil Doncaster and David Longmuir, had warned of potential financial collapse if Rangers were made to join the Third Division, because the SPL's £80m TV deal and its sponsorships depend on both Celtic and Rangers being in the league.
SFL clubs, which have no TV deal, have insisted they will hold the SPL to the £2m it is obliged to pay under the original agreement when the then top 10 SFL clubs broke away to form the SPL in 1998.
Last Friday the SFL clubs nevertheless voted to put into the Third Division the Rangers club to be formed by Charles Green's Sevco company, which has bought Ibrox and the old Rangers' other assets from the club's administrators.
The 11 SPL clubs which met on Monday agreed to invite Dundee, who finished second in the SFL last season, to take the place of Rangers for the coming season, rather than allow Dunfermline, who finished bottom of the SPL, to stay up.
