I see, sorry if I sounded pushy. From your original post it wasn't clear to me that you already had this information.
Just to finish my humble contribution (I can only research online given that I'm in Brazil), I would like to reaffirm that I think the translation of Eugenie's will had the address wrongly translated.
This advertisement from the same period states the address as "Richmond, under the Hill, near the bridge", which I think was the intented address instead of "Lowerhill near Richmond", otherwise Mrs. Cholmley would have had to be leaving outside Richmond in a nearby place, which wasn't the case. The Lower road under the Hill (Richmond Hill) near the bridge (Richmond Bridge) lead to Petersham Road.
The ad file is too big to be attached, so here's the transcript
Morning Advertiser London 3 Aug 1810
Page 4
Richmond under the Hill, near the Bridge - By Mr. WHITE, on the Premisses, by Order of the Executors, on Monday, August 6, at One, in Five Lots, A Valuable LEASEHOLD ESTATE, most derirably and delightfully situate on the bank of the Thames, in the lower road under the Hill, near Richmond Bridge; consisting of four Dwelling Houses, with gardens, coach house and stables, &c. late property of Mr. Benjamin Fox, deceased ; held for an unexpired term of 55 years....
Another evidence that this might be the right name of her address is that Mrs. Charlotte Ann Broome former Francis (nee Burney), sister of Leonard Smelt's friend novelist Frances "Fanny" Burney, lived at the same area in 1818, as the envelope addressed to her can confirm.
*Location:Literary and Historical Manuscripts--Bound
*Call Number: Southey 1
Record ID:137520
Accession Number:MA 63.6
Author/Creator:Southey, Robert, 1774-1843.
Biographical Data:English poet and man of letters.
Title:Autograph letter signed : Keswick, to Mrs. Broome, 1818 Jan. 28.
Date of Writing: 1818 Jan. 28.
Related Records
FULL TITLE AUTHOR/CREATOR DATES
Collection of letters and documents of Robert Southey, 1795-1837. Southey, Robert, 1774-1843. 1795-1837
Description:1 item (1 p., with address) ; 22.6 cm
Summary:Promising to send her verses on the death of her son Ralph.
Credit:Purchased by Pierpont Morgan, 1905.
Notes:Address panel with seal and postmarks, and addressed "For / Mrs. Broome / Under the Hill / Richmond / Surry."
Formerly bound with a collection of letters and papers of Rear Admiral James Burney (MA 38).
Part of a collection of letters and manuscripts of Robert Southey. Items have been cataloged individually; see collection-level record for more information.
Provenance:Listed in Bernard Quaritch catalog no. 234 (1904), no. 42; purchased by Pierpont Morgan from Quaritch in 1905.
Associated Names:Broome, Charlotte Ann, recipient.
Formatted Place:England--Cumberland--Keswick.
https://corsair.themorgan.org/vwebv/holdingsInfo?bibId=137520I hope someone local will help you further. Cheers!
PS (sorry!) I wonder if Eugenie met Leonard Smelt through Frances Burney who could have know Wolff and Deken via literary figures and French exiles?
"When the French Revolution began in 1789, Burney was among many literary figures in England who sympathized with its early ideals of equality and social justice.[6] During this period Burney became acquainted with some French exiles known as "Constitutionalists", who had fled to England in August 1791 and were living at Juniper Hall, near Mickleham, Surrey, where Burney's sister Susanna lived. She quickly became close to General Alexandre d'Arblay (1754-1818), an artillery officer who had been adjutant-general to Lafayette. D'Arblay taught her French and introduced her to the writer Germaine de Staël."
https://en.wikipedia.org/wiki/Frances_Burney