Trad Morgans can be prone to suffering with out of balance wheels, particularly the front causing shimmy.

I know you're not going ahead with it, but I'd also want to be certain the tyre sealer was compatible with the sealing band in the wheel rim...

Graham (G4FUJ)

Sold L44FOR 4/4 Giallo Fly
'09 Gen2 MINI Cooper ragtop
'90 LR 90 SW